Wafer thinning apparatus and thinning method

Abstract

The application provides a wafer thinning device and a thinning method, and belongs to the technical field of integrated circuit manufacturing; wherein the thinning method comprises: obtaining light intensity values corresponding to light signals in the process of grinding a wafer by the wafer thinning device; and determining a temperature adjustment strategy for grinding the wafer by the wafer thinning device based on the light intensity values. The light signals are emitted by nano-particles in a grinding wheel of the wafer thinning device under the excitation of grinding heat. The application improves the accuracy of grinding heat monitoring in the process of grinding the wafer by the wafer thinning device, so that temperature control measures can be timely and effectively implemented according to the accurate grinding heat monitoring results, and defects such as warping and burning of the wafer due to excessively high temperature are avoided, thereby improving the grinding precision and yield of the wafer.

Description

Technical Field

[0001] This application belongs to the field of integrated circuit manufacturing technology, and more specifically, relates to a wafer thinning device and a thinning method. Background Technology

[0002] 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.

[0003] 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 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.

[0004] 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 ≤10μm, TTV ≤1.5μm, and Ra ≤1μm) while also considering manufacturing costs and production efficiency.

[0005] During wafer grinding, grinding heat is generated due to intense friction between the abrasive grains and the wafer surface, plastic deformation, and material shearing. This grinding heat can cause surface damage to the wafer and affect grinding accuracy. Existing grinding wheels have at least the following shortcomings in thermal management during wafer grinding:

[0006] Relying on external temperature sensors to monitor grinding temperature makes it difficult to accurately capture the real-time temperature of the interface between the grinding wheel and the wafer, resulting in a large error in grinding thermal monitoring.

[0007] The lack of a temperature feedback mechanism leads to a delayed response, making it impossible to take effective cooling measures in a timely and accurate manner based on the grinding heat. This results in defects such as warping, microcracks, or surface damage in the wafer due to localized overheating, which seriously affects chip yield and grinding accuracy. Summary of the Invention

[0008] Based on the above problems, this application provides a wafer thinning apparatus and a thinning method, which aims to at least solve or alleviate one of the technical problems existing in the prior art.

[0009] A first aspect of this application provides a wafer thinning apparatus, including: a grinding device, an adsorption platform, a collector, and a controller.

[0010] The adsorption platform is used to support the wafer and drive its rotation;

[0011] The grinding device is raised and lowered above the adsorption platform, and its lower part has a grinding wheel for grinding wafers; the grinding wheel includes a grinding block, the grinding block has nanoparticles, the nanoparticles have thermoluminescence properties, and are used to emit light signals of different intensities under different grinding thermal excitation;

[0012] The collector is used to collect optical signals;

[0013] The controller is electrically connected to the collector to determine the light intensity value corresponding to the light signal and to generate a temperature regulation strategy for grinding the wafer based on the light intensity value.

[0014] In one embodiment, the grinding block comprises diamond abrasive grains with nanoparticles loaded on its surface.

[0015] In one embodiment, the nanoparticles are composed of lanthanide metal oxides.

[0016] In one embodiment, the nanoparticles include one or more of europium oxide, cerium oxide, gadolinium oxide, and samarium oxide.

[0017] In one embodiment, the grinding apparatus includes:

[0018] The feeding component is positioned above the adsorption platform and moves up and down relative to it. The feeding component is electrically connected to the controller, which is configured to control the feeding speed of the feeding component under different temperature regulation strategies.

[0019] The rotating shaft is driven and raised by the feed assembly, and the grinding wheel is connected to the lower end of the rotating shaft.

[0020] In one embodiment, the controller includes:

[0021] A comparator is used to compare the light intensity value with a preset light intensity threshold to determine the range to which the light intensity value belongs, so as to determine the temperature adjustment strategy for grinding the wafer in the current wafer thinning equipment based on the range; the preset light intensity threshold is determined by a preset temperature threshold and the correspondence between temperature value and light intensity value.

[0022] In one embodiment, the controller further includes:

[0023] The first actuator, electrically connected to the comparator and the coolant flow regulating device, is used to control the coolant flow rate according to the range of the light intensity value: if the light intensity value is in the first range, the coolant flow rate is adjusted to the preset initial flow rate; if the light intensity value is in the second range, the initial flow rate is increased by a first proportion; if the light intensity value is in the third range, the initial flow rate is increased by a second proportion.

[0024] The second actuator, electrically connected to the comparator and the feed assembly, is used to adjust the feed speed according to the range of the light intensity value: if the light intensity value is in the first range, the feed speed is controlled to be the preset initial feed speed; if the light intensity value is in the third range, the feed speed is controlled to be reduced by a predetermined percentage based on the initial feed speed.

[0025] A second aspect of this application provides a thinning method, comprising the following steps:

[0026] The light intensity value corresponding to the light signal during the wafer grinding process of the wafer thinning equipment is obtained; the light signal is emitted by nanoparticles in the grinding wheel under the thermal excitation of grinding.

[0027] The temperature control strategy for grinding wafers in the current wafer thinning equipment is determined based on the light intensity value.

[0028] In one embodiment, determining the temperature regulation strategy for grinding the wafer using the current wafer thinning equipment based on the light intensity value includes:

[0029] The light intensity value is compared with a preset light intensity threshold to determine the range to which the light intensity value belongs; the preset light intensity threshold is determined by a preset temperature threshold and the correspondence between temperature value and light intensity value;

[0030] The temperature regulation strategy for grinding wafers in the current wafer thinning equipment is determined based on the range.

[0031] In one embodiment, determining the temperature regulation strategy for grinding the wafer in the current wafer thinning equipment based on a range includes:

[0032] In response to the light intensity value being in the first range, a first temperature regulation strategy is adopted, including: adjusting the coolant flow rate to a preset initial flow rate and controlling the feed rate to a preset initial feed rate;

[0033] In response to the light intensity value being in the second range, a second temperature control strategy is adopted, including: increasing the initial flow rate by a first proportion to cool the wafer grinding process; and

[0034] In response to the light intensity value being in the third range, a third temperature regulation strategy is adopted, including: increasing the second proportion based on the initial flow rate, and controlling the feed rate to decrease by a predetermined proportion based on the initial feed rate.

[0035] In one embodiment, the method further includes:

[0036] In response to a change in the interval to which two consecutive determined light intensity values ​​belong, including a change from the second or third interval to the first interval, and the light intensity values ​​determined for a subsequent preset number of consecutive times are all within the first interval;

[0037] Adjust the temperature regulation strategy to the first temperature regulation strategy corresponding to the first interval.

[0038] In one embodiment, the method further includes:

[0039] Obtain the average of light intensity values ​​determined by a specified number of consecutive iterations;

[0040] The temperature control strategy for grinding wafers using the current wafer thinning equipment, based on light intensity values, includes:

[0041] The temperature control strategy for grinding wafers in the current wafer thinning equipment is determined based on the mean value of light intensity.

[0042] The beneficial effects of the wafer thinning equipment and thinning method provided in this application embodiment are as follows:

[0043] The wafer thinning equipment of this application adds nanoparticles to the composition of the grinding wheel block. The nanoparticles have thermoluminescence properties and emit light signals of different intensities due to different grinding heat during the grinding process of the wafer. Therefore, the temperature adjustment strategy for grinding the wafer can be determined according to the different light intensity values.

[0044] This application can determine grinding heat based on light intensity values, effectively improving the accuracy of grinding heat monitoring during wafer grinding. This allows for timely and effective temperature control measures based on accurate grinding heat, preventing wafers from warping, burning, or other defects due to excessive temperature, and improving wafer grinding precision and yield.

[0045] The embodiments of this application improve the accuracy of wafer grinding thermal monitoring, thereby enabling more accurate temperature control measures and avoiding problems such as coolant waste and insufficient cooling.

[0046] This application embodiment adds nanoparticles to the grinding wheel block, utilizing the interfacial stress-induced effect to achieve lattice dislocation pinning strengthening, thereby enhancing the toughness and bonding strength of the grinding wheel block. On the one hand, this can improve the service life of the grinding wheel and reduce the frequency of grinding wheel replacement in wafer thinning equipment. On the other hand, it can also reduce abrasive grain breakage and shedding, improve grinding stability, and thus achieve the effect of improving wafer grinding accuracy and yield. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of the structure of a wafer thinning apparatus according to one embodiment of this application;

[0049] Figure 2 for Figure 1 Side view of the grinding device and adsorption platform of the wafer thinning equipment;

[0050] Figure 3 for Figure 2 Bottom view of the intermediate grinding wheel;

[0051] Figure 4 This is a flowchart of a thinning method provided in one embodiment of this application;

[0052] Figure 5 for Figure 4 Flowchart of one embodiment of step S43;

[0053] Figure 6 This is a graph showing the correspondence between temperature values ​​and light intensity values ​​according to one embodiment of this application;

[0054] Figure 7 This is a flowchart of a method for determining a light intensity threshold according to an embodiment of this application;

[0055] Figure 8 This is a flowchart of a specific embodiment of the thinning method of this application;

[0056] Figure 9 This is a structural block diagram of a thinning device provided in one embodiment of this application;

[0057] Figure 10 This is a schematic block diagram of an electronic device provided in an embodiment of this application.

[0058] Figure label:

[0059] 1. Equipment base; 2. Grinding device; 21. Rotary shaft; 22. Grinding wheel; 221. Substrate; 222. Grinding block; 3. Adsorption platform; 31. Chuck spindle; 32. Worktable; 33. Adsorption plate; 4. Rotary disk; 50. Thinning device; 51. Light intensity value acquisition unit; 52. Strategy determination unit; 600. Electronic equipment; 601. Processor; 602. Input device; 603. Output device; 604. Memory; 605. Communication bus. Detailed Implementation

[0060] To enable those skilled in the art to better understand the technical solutions in the embodiments of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of this application.

[0061] 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."

[0062] 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.

[0063] 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 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 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.

[0064] 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.

[0065] 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.

[0066] It should be understood that, unless the context clearly states 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, "comprising" and / or "including" as used herein specify 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. Some embodiments of this application are described in detail below with reference to the accompanying drawings. Where there is no conflict between the embodiments, the following embodiments and features can be combined with each other. The steps in the following method embodiments are for illustrative purposes only and are not intended to limit this application.

[0067] 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.

[0068] Furthermore, a column is provided at the end of the equipment base 1, and a grinding device 2 is provided on the side of the column. There are two grinding devices 2, corresponding to a rough grinding section and a fine grinding section. The two have similar structures and are both equipped with a feed assembly that drives the grinding wheel 22 to move up and down and a mechanism that drives the grinding wheel to rotate along the rotating shaft 21. The feed assembly is set above the adsorption platform and moves up and down relative to it. The feed assembly includes a lifting motor, 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 21, thereby changing the position of the grinding wheel 22 relative to the adsorption platform 3.

[0069] The adsorption platform 3 is used to support the wafer and drive the wafer 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 22 that can rotate circumferentially to grind the wafer.

[0070] The grinding device 2 includes a feed assembly, a rotary shaft 21, and a grinding wheel 22. The grinding block 222 in the grinding wheel 22... Figure 3(Shown) This is used for grinding wafers. The grinding wheel 22 can be a cup-shaped grinding wheel, mounted at the lower end of the rotating shaft 21. The rotating shaft 21 is used to rotate the grinding wheel 22 about its axis of rotation. The rotating shaft 21 is drive-connected to a feed assembly, which drives the rotating shaft 21 and the grinding wheel 22 to move up and down synchronously. When the wafer needs grinding, the grinding wheel 22 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 22 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 22. The feed assembly has a known construction and includes, for example, multiple linear guides that guide the movement direction of the rotating shaft 21 and a ball screw-slider mechanism that moves the rotating shaft 21 up and down.

[0071] Reference Figure 3 , it is Figure 2 A bottom view of the grinding wheel 22 shows that the grinding wheel 22 includes a substrate 221 and a plurality of grinding blocks 222 disposed on the surface of the substrate 221 for grinding the wafer. The grinding blocks 222 can be rounded rectangles or fan shapes. At least a portion of the grinding blocks 222 is embedded in an annular groove and spaced apart from each other on the substrate 221. The substrate 221 can be fastened to the lower end of the rotating shaft 21 by bolts.

[0072] In one embodiment, the raw materials of the grinding block 222 include: diamond abrasive grains, nanoparticles, resin binder, and pore-forming agent. The nanoparticles are loaded on the surface of the diamond abrasive grains, thus the surface of the grinding block 222 contains nanoparticles, and these nanoparticles exhibit thermoluminescence properties. During the grinding process of the wafer by the grinding wheel 22, different grinding heat can excite light signals of different intensities.

[0073] In one embodiment, the nanoparticles are composed of lanthanide metal oxides, which exhibit thermoluminescence. This application innovatively introduces lanthanide metal oxide nanoparticles as a functional interface reinforcement phase, loaded onto the surface of diamond abrasive grains. Lanthanide metal oxides not only possess high hardness, high melting point, and excellent thermal stability, but also exhibit unique thermoluminescence properties. This property refers to the phenomenon of photons emitted by the material due to thermal excitation during heating or grinding, which can serve as a sensitive signal source for in-situ monitoring of interfacial stress and temperature changes, indirectly reflecting the thermo-mechanical coupling state of the grinding zone.

[0074] From an interfacial chemistry perspective, the surface of lanthanide metal oxide nanoparticles is rich in Lewis acid sites (such as uncoordinated sites). Ions can undergo strong chemical adsorption or coordination with oxygen-containing functional groups (such as carboxyl and hydroxyl groups) introduced into the diamond surface after pretreatment (such as acidification or hydroxylation), forming a strong Ln–O–C covalent interface bridge. This interface layer not only significantly enhances the chemical bonding force between diamond and the binder (such as ceramic, metal, or resin-based materials), reducing the tendency of abrasive grains to detach under high-speed and high-load conditions, but also effectively transmits and disperses grinding stress, delaying the initiation and propagation of microcracks, thereby improving the overall mechanical properties of the grinding wheel, such as bending strength, impact toughness, and wear resistance.

[0075] In this embodiment, lanthanide metal oxides are used as nanoparticles loaded onto the diamond surface, which improves the overall mechanical properties and grinding stability of the grinding wheel. Compared with other metal oxides, the unfilled 4f orbitals in lanthanide metals can form strong coordination bonds with hydroxyl oxygen atoms at defect sites on the diamond surface. This interaction can build a stable interface between the diamond and the binder, effectively preventing diamond detachment during grinding and inhibiting crack propagation, thereby significantly extending the service life of the grinding wheel 22. This embodiment adds specific nanoparticles to the grinding wheel block to achieve nanoscale functional modification and strengthening of the diamond abrasive surface. Specifically, the selected nanoparticles (such as lanthanide metal oxides) are firmly loaded onto the diamond surface through chemical adsorption or physical anchoring. During grinding, the difference in thermal expansion coefficients between them and the diamond, as well as the interfacial lattice mismatch, induces a controllable micro-interfacial stress field. This stress field can further induce lattice distortion, forming stable dislocation pinning centers, effectively hindering the initiation and propagation of microcracks inside the diamond, thereby achieving a dislocation strengthening mechanism.

[0076] Meanwhile, lanthanide metal oxide nanoparticles possess high thermal stability and mechanical strength, and can undergo localized chemical bonding with the diamond surface under high-temperature grinding conditions, forming strong interfacial coupling. Under periodic grinding stress, the stress field gradient formed around these nanoparticles can significantly constrain the slip and multiplication of dislocations in the diamond lattice, causing dislocation lines to bend and entangle around the particles, consuming crack propagation energy, thereby greatly improving the macroscopic toughness and fracture resistance of diamond abrasive grains.

[0077] Furthermore, this strengthening mechanism also helps enhance the physicochemical bonding strength between diamond and the binder (such as metal, ceramic, or resin-based materials). Nanoparticles, acting as an interfacial transition layer, can alleviate stress concentration caused by differences in material properties, improve load transfer efficiency, and reduce the tendency for abrasive grains to detach. Ultimately, the overall mechanical properties of the grinding wheel 22, such as impact resistance, wear resistance, and fatigue life, are significantly optimized, vibration and noise during the grinding process are reduced, and process stability and the surface quality of the machined parts are simultaneously improved.

[0078] In summary, this embodiment achieves a systematic improvement in the performance of diamond abrasive grains from microscopic strengthening to macroscopic performance through the stress-induced dislocation pinning effect induced by nanoparticle interface modification, providing a new approach for the design of high-precision and high-efficiency grinding tools.

[0079] In one embodiment, the nanoparticles comprise: europium oxide cerium oxide Gadolinium oxide samarium oxide One or more of the following, preferably, the nanoparticles are europium oxide. Europium oxide exhibits unique interface enhancement advantages in this application, mainly due to its special electronic structure and variable valence properties: A reversible and sensitive redox synergistic mechanism exists. During high-temperature grinding or interfacial reactions, Eu ions can dynamically switch between their +2 and +3 valence states according to the local chemical environment. On the one hand, this enhances the charge interaction with carbon atoms on the diamond surface, forming a stronger interfacial bond. On the other hand, this valence state change can induce lattice distortion and stress field modulation, further promoting dislocation pinning and interfacial strengthening effects, thereby significantly improving the interfacial bonding strength and load transfer capability between the nanoparticle-supported layer and the diamond matrix.

[0080] Furthermore, europium oxide exhibits excellent thermal stability and radiative energy dissipation characteristics, maintaining the integrity of the interfacial structure under the high temperature and high stress conditions caused by high-speed grinding, and avoiding a decrease in bonding strength due to thermal softening or degradation of the interfacial reaction layer. Compared with other lanthanide oxides, europium oxide... The synergistic effect of the dual-valent state is more significant, making it more advantageous in strengthening the diamond-bond interface under the same conditions. This, in turn, more effectively inhibits abrasive shedding, delays the propagation of microcracks, and ultimately improves the overall wear resistance of the grinding wheel and the stability of the grinding process.

[0081] In one embodiment, nanoparticles can be loaded onto the surface of diamond abrasive grains using the following method:

[0082] (1) Dissolve hydrated nitrate in water, add a chelating agent, stir evenly, adjust the pH to 6-7, and stir at 60-80℃ for 2-3 hours to form a stable sol. The hydrated nitrate, as a precursor, has a metal element that corresponds to the metal element in the final nanoparticles. For example, it could be... One of the following is a list of chelating agents. The chelating agent can be one of citric acid, tartaric acid, or ethylenediaminetetraacetic acid, and the molar ratio of hydrated nitrate to the chelating agent is 1:1 to 2. Preferably, the chelating agent is ethylenediaminetetraacetic acid, and the molar ratio of hydrated nitrate to the chelating agent is 1:2.

[0083] (2) Add diamond to the above sol and ultrasonically disperse for 0.5-1 h to fully wet the diamond surface with the sol. Then dry to obtain diamond particles coated with dry gel. The drying can be carried out at 80-100℃ for 12-24 h. The diamond can be untreated diamond or diamond with pretreated surface (such as acidification or hydroxylation).

[0084] (3) Finally, in an air atmosphere, the temperature is increased to 600~800℃ at a heating rate of 5℃ / min and calcined for 2~4h to decompose the dry gel into metal oxide nanoparticles and load them onto the diamond surface. The weight gain of the diamond after sintering is 20~30%.

[0085] Both the sol preparation and loading processes are liquid-phase methods, which are simple to operate, low in cost (chelating agents are recyclable), have good reproducibility, and are easy to scale up. In the above methods, the chelating agent can bind to metal ions (such as...) through coordination bonds. The ion complexes combine to form stable cyclic complexes, thereby regulating the hydrolysis rate of metal ions, inhibiting aggregation, ensuring the dispersibility and uniformity of the sol, and improving the coating effect. The sol-state ion complexes are highly active and can form "complex-diamond" hydrogen bonds or coordinate bonds with the hydroxyl oxygen atoms at defect sites on the diamond surface through the functional groups of the chelating agent (such as carboxyl and hydroxyl groups). After calcination, the chelating agent decomposes, and the metal oxide directly forms covalent bonds with the diamond surface. Compared to physical mixing, the interfacial bonding energy is higher, effectively preventing diamond from falling off during grinding and improving wafer thinning.

[0086] In one embodiment, the grinding block 222 comprises the following raw materials by mass ratio: 40-60 wt% diamond, 40-50 wt% resin binder, and 5-10 wt% pore-forming agent. The resin binder can be one of phenolic resin, polyimide resin, or epoxy resin, and the pore-forming agent can be one of ammonium bicarbonate, sodium bicarbonate, or ammonium carbonate. The average particle size of the diamond can be 10-100 μm. Diamond possesses extremely high wear resistance and sharpness, enabling rapid grinding of materials. 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.

[0087] In one embodiment, the grinding block 222 can be prepared by mixing diamond loaded with nanoparticles, a resin binder, and a pore-forming agent in a certain mass ratio, and ball milling during the mixing process for 4-6 hours to ensure uniform mixing of the materials. A ball mill can be used for ball milling.

[0088] Pressing and curing: The mixed materials are placed into a mold and pressed into shape on a hot press at a pressure of 50-100 MPa, a holding time of 30-50 min, and a pressing temperature of 170-230℃. Subsequently, it is cured at 170-230℃ for 12-18 h.

[0089] In one embodiment, the grinding wheel 22 can be prepared by the following method: the grinding block 222 is bonded to the grinding wheel substrate with an adhesive, the adhesive is applied evenly and the thickness is controlled at 0.1~0.2mm, and after bonding, it is cured at 80~100℃ for 2~4h to obtain the grinding wheel 22.

[0090] In one embodiment, the light signal emitted by the nanoparticles can be collected by a collector. In one embodiment, the collector faces the grinding block 222 of the grinding wheel 22. For example, the collector can be positioned to the side of the adsorption platform 3 and below the grinding wheel 22. Figure 2 As shown, the light signal emitted by nanoparticles is collected in real time from bottom to top. The collector can be a photoelectric sensor, which is composed of a photodiode array.

[0091] 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 ceramic material, 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 22, or the grinding device 2 may be equipped with a tilting structure that tilts the rotation axis 21. This allows adjustment of the contact between the grinding block 222 and the wafer to grind the wafer into the desired shape.

[0092] The operation of the grinding device 2 is controlled by a controller. The controller controls the various components that make up the grinding device 2. The controller includes, for example, a CPU and a memory. Furthermore, the controller's functions can be implemented through software control or hardware operation. For example, the controller is electrically connected to the feed assembly and controls the feed speed of the feed assembly under different temperature regulation strategies. In other words, the controller can control the movement of the feed assembly, the rotary axis 21, and the chuck spindle 31 according to preset grinding process parameters, such as feed speed and rotational speed, to achieve an automated grinding process. Simultaneously, the controller also has fault diagnosis and alarm functions, capable of monitoring the operating status of each part of the equipment in real time. When abnormalities occur, it promptly issues alarms and takes corresponding protective measures to ensure the safety of the equipment and operators.

[0093] like Figure 2 As shown, the controller is electrically connected to the collector and is used to determine the light intensity value corresponding to the light signal collected by the collector, and to generate a temperature regulation strategy for grinding the wafer based on the light intensity value.

[0094] In one embodiment, to accurately determine and respond to the light intensity value corresponding to the light signal collected by the collector, this application constructs a closed-loop control architecture based on light intensity segmentation identification. To further determine the light intensity value corresponding to the light signal collected by the collector, the controller includes: a comparator, used to compare the light intensity value with a preset light intensity threshold to determine the interval to which the light intensity value belongs, so as to determine the temperature adjustment strategy for grinding the wafer in the current wafer thinning equipment based on the interval.

[0095] The preset light intensity threshold is not set by human experience, but is determined by a preset temperature threshold and the correspondence between temperature and light intensity values. This mapping relationship can be established through preliminary process experiments or theoretical modeling. For example, grinding temperature can be simultaneously detected by thermocouples or infrared temperature measuring devices and fitted with the corresponding light signal intensity to establish a temperature-light intensity function model or a corresponding lookup table. This transforms the temperature control requirements into photoelectrically detectable dimensions, providing a reliable basis for optical temperature measurement and feedback control.

[0096] In one embodiment, to implement a temperature regulation strategy for grinding the wafer in the current wafer thinning equipment based on a range determination, further, as... Figure 2 As shown, the controller also includes:

[0097] A first actuator, electrically connected to a comparator and a coolant flow regulating device, is used to control the coolant flow rate according to the range of light intensity values. In one embodiment, it specifically includes:

[0098] When the light intensity value is within the first range, the coolant flow rate is adjusted to a preset initial flow rate; that is, the default cooling parameters are used within the first range. In one embodiment, the coolant flow rate adjustment device can be a coolant pump.

[0099] When the light intensity value is in the second range, a first proportion is added to the initial flow rate; the first proportion can be in the range of 10% to 30%, and for example, 20% is preferred under certain operating conditions.

[0100] When the light intensity value is in the third range, a second proportion is added to the initial flow rate; the range of the second proportion can be 40% to 60%, for example, 50% can be used in some specific applications.

[0101] It should be noted that the specific values ​​of the first and second ratios can be adapted and adjusted according to different models of equipment, wafer materials, grinding process requirements, or coolant properties. In other embodiments, the first ratio may also be 15%, 18%, 25%, etc., and the second ratio may be 45%, 50%, 55%, etc. The range can be appropriately expanded or narrowed according to actual thermal management needs, and should not be limited to a specific value, so as to avoid limiting the scope of protection due to the specific implementation description.

[0102] Furthermore, in some extended implementation schemes, the first and second ratios can also be dynamically calculated based on real-time heat load or historical process data, rather than fixed values, thereby further improving the adaptability and accuracy of temperature control.

[0103] The second actuator is electrically connected to the comparator and the feed assembly, for example... Figure 2 As shown, the motor electrically connected to the control feed component is used to adjust the feed speed of the feed component according to the range of light intensity values. In one embodiment, it specifically includes:

[0104] When the light intensity value is within the first range, the feed speed is controlled to the preset initial feed speed; that is, the preset initial feed speed is used within the first range. Specifically, the feed speed of the feed component can be adjusted by controlling the motor of the feed component.

[0105] When the light intensity value is in the third range, the feed rate is reduced by a predetermined percentage from the initial feed rate. This predetermined percentage can be flexibly set within a certain range according to actual process requirements, wafer material, or equipment characteristics. As an example, the predetermined percentage can range from 20% to 40%, such as 25%, 30%, or 35%. In some specific application scenarios, a reduction percentage of 30% can be used.

[0106] Figure 2 The downward arrow on the coolant flow regulator indicates the direction of coolant flow, while the other arrows indicate the direction of signal flow.

[0107] Through the above-mentioned dual actuator linkage control, this embodiment not only achieves a fast and accurate response to grinding temperature, but also indirectly reflects the temperature status through light intensity signals. This overcomes the limitations of traditional direct temperature measurement, such as response lag and inconvenient installation. It is especially suitable for high-precision grinding scenarios that are sensitive to temperature, such as wafer thinning, and significantly improves process controllability and product yield. It has outstanding innovation and practicality.

[0108] The wafer thinning equipment provided in this application innovatively introduces functional nanomaterials into the composition design of the grinding block 222 of the grinding wheel 22. Specifically, by adding nanoparticles with thermoluminescent properties during the preparation of the grinding wheel binder or grinding block, and firmly loading them onto the surface of the diamond abrasive grains, an intelligent grinding state sensing and feedback unit is constructed.

[0109] During wafer grinding, the intense friction in the grinding zone generates significant heat, which directly excites nanoparticles (such as selected lanthanide metal oxides) to emit light signals whose intensity is closely related to temperature. This luminescence phenomenon originates from a thermoluminescence mechanism: under thermal excitation, the electrons inside the nanoparticles undergo energy level transitions, releasing photons of specific wavelengths. The light intensity has a continuous and calibrable correlation with the ambient temperature. By capturing this light signal in real time using a high-speed optical acquisition device (such as a photoelectric sensor or CCD detector) and converting it into an electrical signal for processing, the instantaneous temperature of the grinding zone can be accurately and in real time calculated based on the continuous changes in light intensity. This allows for the dynamic formulation and execution of precise temperature control strategies.

[0110] Compared to traditional indirect temperature measurement methods such as thermocouples or infrared thermometry, this direct monitoring method based on the luminescent properties of built-in nanoparticles offers significant advantages. It integrates the sensing unit directly into the grinding contact area, achieving "in-situ" monitoring of the grinding heat source. This avoids measurement errors caused by installation location limitations, response lag, or signal transmission interference in traditional methods, greatly improving the spatiotemporal resolution and accuracy of grinding thermal monitoring. Based on this high-precision thermal information, the controller can promptly and effectively trigger corresponding temperature control measures, such as precisely adjusting coolant flow or grinding feed parameters, thereby strictly controlling the grinding temperature within the process window. This not only fundamentally avoids thermal defects such as warpage, microcracks, and phase transformation burns caused by localized overheating of the wafer, but also effectively improves key quality indicators such as wafer thickness uniformity and surface flatness, significantly enhancing the overall processing accuracy and product yield of wafer thinning.

[0111] Furthermore, the improved monitoring accuracy brought about by this embodiment also results in significant process optimization and resource efficiency benefits. Traditional cooling strategies often employ overly conservative coolant supply methods due to safety margin considerations, easily leading to substantial coolant waste and increased subsequent processing costs. This solution, however, can accurately identify the actual heat demand during grinding, achieving "on-demand distribution" of coolant. This avoids resource waste when cooling is unnecessary or demand is low, while ensuring sufficient cooling when the heat load increases sharply. Thus, while ensuring process safety, it significantly reduces coolant consumption, demonstrating excellent economic efficiency and environmental friendliness. Simultaneously, by avoiding both "insufficient cooling" and "overcooling" extreme conditions, it also ensures the thermal stability of the grinding process, further promoting the uniformity and reliability of machining quality.

[0112] Reference Figure 4 This is a flowchart of a wafer thinning method provided in an embodiment of this application. The method uses the wafer thinning equipment of this application to grind the wafer and includes the following steps:

[0113] S41. Obtain the light intensity value corresponding to the optical signal during the wafer grinding process of the wafer thinning equipment;

[0114] The wafer thinning apparatus of this application contains nanoparticles in its grinding wheel. These nanoparticles exhibit thermoluminescence properties. During the wafer grinding process, the grinding heat excites these nanoparticles to emit light, and the intensity of the light signal emitted varies depending on the grinding heat. Using these nanoparticles as... For example, according to the Boltzmann distribution principle, Ions in In crystals, due to having Leapfrog channel, Ions undergo electronic transitions under the thermal excitation of grinding, releasing red light. The emission wavelength is concentrated at 612nm, and the intensity of the red light signal increases with increasing temperature.

[0115] In this embodiment, the light signal emitted by the wafer thinning equipment during the wafer grinding process can be collected by the collector and further converted into an electrical signal. For example, if the collector is a photoelectric sensor, the photoelectric sensor can convert the collected light signal into a voltage signal. Then, by identifying the voltage value, the light intensity value can be obtained by the light intensity detection sensor.

[0116] It should be noted that the signal converted by the collector is not limited to voltage signals, but can also be other forms of intensity-identifiable signals. This application does not impose specific limitations on this. Any electrical or digital signal form that can effectively characterize the intensity of the optical signal and can be identified and processed by subsequent control circuits falls within the protection scope of this application. This includes, but is not limited to, current signals, frequency signals, pulse width modulation (PWM) signals, or digital signals quantized by an analog-to-digital converter (ADC). The choice of signal form can be flexibly determined based on factors such as the circuit design of the specific system, anti-interference requirements, and signal transmission distance. This application does not impose any restrictions on the specific electrical signal representation form of the optical intensity value.

[0117] Understandably, in order to improve the compactness and reliability of the system, the optical signal can also be converted into an electrical signal by the photoelectric converter built into the controller, or the optical signal can be converted into other forms of intensity-identifiable signals by other types of converters built into the controller.

[0118] Furthermore, the controller can also incorporate other types of dedicated signal converters. For example, it can incorporate a voltage-to-frequency converter (VFC) to convert the voltage signal after photoelectric conversion into a square wave signal whose frequency is proportional to the light intensity; or it can incorporate a high-speed ADC to directly quantize the analog light intensity signal into digital code. These converted, other forms of intensity-identifiable signals (such as frequency and digital values) can also be accurately read by the controller's logic units (such as CPU or FPGA) and used for subsequent comparison and judgment logic.

[0119] In one embodiment, the optical signal output by the collector can be acquired in real time. The collector can acquire the optical signal at a preset sampling frequency and output it. For example, the collector can sample one data point every 0.145ms, corresponding to a sampling frequency of 6.9kHz.

[0120] In one embodiment, to avoid misjudgment due to signal fluctuations, the average of the light intensity values ​​determined a specified number of times can be obtained, and the average of the light intensity values ​​can be used as the output light intensity value. For example, the average of five consecutive determined light intensity values ​​can be calculated as the output light intensity value.

[0121] This embodiment uses a moving average method to process light intensity values, which can effectively suppress noise interference, avoid misjudgments caused by signal fluctuations, and effectively improve the accuracy of light intensity value determination.

[0122] S42. Determine the temperature regulation strategy for grinding wafers in the current wafer thinning equipment based on the light intensity value.

[0123] In one embodiment, determining the temperature regulation strategy for grinding the wafer using the current wafer thinning equipment based on the light intensity value includes:

[0124] The light intensity value is compared with a preset light intensity threshold to determine the range to which the light intensity value belongs, thereby determining the temperature adjustment strategy for grinding the wafer in the current wafer thinning equipment based on the light intensity range. The preset light intensity threshold is determined by a preset temperature threshold and the correspondence between temperature values ​​and light intensity values.

[0125] In one embodiment, such as Figure 5 As shown, determining the temperature control strategy for grinding wafers using the current wafer thinning equipment based on light intensity values ​​includes the following steps:

[0126] S421. Determine whether the light intensity value is less than the first light intensity threshold.

[0127] The first light intensity threshold is a predetermined safe range threshold for grinding wafers with an abrasive wheel. This first light intensity threshold reflects a low grinding temperature, indicating that the wafer is at a safe grinding temperature. This step is to perform a preliminary judgment of the light intensity value, comparing the light intensity value determined in step S41 with the first light intensity threshold to determine whether the current light intensity value is less than the first light intensity threshold. If so, it indicates that the currently monitored light signal intensity is weak, and the corresponding grinding zone temperature is low, within the allowable safe range, and the process proceeds to step S422; if not, it means that the current light intensity value on the surface has exceeded the low temperature range corresponding to the first light intensity threshold, and the grinding temperature may be rising or has exceeded the safe range, and the process proceeds to step S423 to perform further judgment.

[0128] S422, the light intensity value is in the first range, execute the first temperature adjustment strategy.

[0129] This step determines that the light intensity value is within a first interval if the current light intensity value is less than a first light intensity threshold. This interval corresponds to the normal low-temperature grinding state. The system then executes a first temperature regulation strategy, which is typically the default baseline control strategy, for example:

[0130] The coolant flow rate is set to the preset initial flow rate; the feed rate is set to the preset initial feed rate.

[0131] In this state, the system maintains its current parameters and there is no need to initiate enhanced cooling or speed reduction operations.

[0132] S423. Determine whether the light intensity value is less than the second light intensity threshold;

[0133] This step involves comparing the current light intensity value with a higher second light intensity threshold when the light intensity value is not less than the first light intensity threshold. If the light intensity value is less than the second light intensity threshold, it indicates that the light intensity has exceeded the safe range but has not reached the highest alarm level. The corresponding grinding temperature shows an upward trend, and the process proceeds to step S424. If not, it indicates that the light intensity is in the high intensity range, the corresponding grinding temperature is too high, and there is a risk of thermal damage. The process proceeds to step S425.

[0134] S424, the light intensity value is in the second range, so the second temperature regulation strategy is executed;

[0135] This step involves determining that the current light intensity value falls between a first light intensity threshold and a second light intensity threshold, thus placing it within a second range. This range corresponds to a warning state of a gradual increase in grinding temperature. The system then executes a second temperature regulation strategy, a preventative and gradual temperature control measure designed to prevent further temperature increases. For example…

[0136] Increase the initial flow rate by a first percentage (e.g., 10-30%) to enhance cooling intensity;

[0137] The feed rate of the feed assembly is kept constant or slightly reduced to avoid generating excessive grinding heat.

[0138] The above measures aim to bring the grinding temperature back to the first range while maintaining production efficiency.

[0139] S425, the light intensity value is in the third range, so the third temperature adjustment strategy is executed.

[0140] This step, assuming the current light intensity value is not less than the second light intensity threshold, determines that the light intensity value falls within the third interval. This interval corresponds to a state where the grinding temperature is too high and there is a risk of emergency thermal overload. The system immediately executes the third temperature regulation strategy. This strategy is a powerful intervention measure that prioritizes cooling and protection, for example:

[0141] To maximize cooling, increase the flow rate by a second percentage (e.g., 40-60%) on top of the initial flow rate.

[0142] The feed assembly is controlled to reduce the initial feed speed by a predetermined percentage (e.g., 30%) to reduce heat generation at the source.

[0143] The core objective of this strategy is to quickly and effectively reduce the temperature of the grinding zone, even at the cost of temporarily reducing efficiency, to ensure that the wafer does not develop defects such as warping, burning, or cracking due to overheating, thus guaranteeing process safety and product yield.

[0144] The principle of this application for determining the temperature regulation strategy of the current wafer thinning equipment based on the light intensity value is as follows: Utilizing the thermoluminescence of nanoparticles, light signals of different intensities are excited by the grinding heat during the wafer grinding process. Since different grinding heats correspond to different temperature values, there is a corresponding relationship between the light intensity value and the temperature value. Therefore, the grinding heat of the wafer grinding can be determined based on the determined light intensity value, and the grinding temperature value can be further inferred. Based on different temperature values, the temperature regulation strategy adopted can be determined. Therefore, the temperature regulation strategy of the current wafer thinning equipment can be determined based on the light intensity value.

[0145] Based on the above principle, in one embodiment of this application, by presetting at least one temperature threshold, multiple temperature range intervals can be obtained based on the at least one temperature threshold, and different temperature range intervals correspond to different temperature adjustment strategies.

[0146] Reference Figure 6 The diagram illustrates an example of the relationship between temperature and light intensity values. In this example, temperature thresholds include 100℃ and 150℃. Temperature ranges include: a first temperature range less than or equal to 100℃, where temperatures are below 100℃ and represent the safe processing temperature range for wafers, allowing wafer thinning equipment to perform thinning using conventional operating and cooling parameters; a second temperature range greater than 100℃ and less than or equal to 150℃, where temperatures exceed the safe processing temperature range for wafers, indicating heat accumulation on the wafer surface and requiring cooling measures; and a third temperature range greater than 150℃, where temperatures indicate excessive heat on the wafer surface, necessitating enhanced cooling. Different ranges correspond to different temperature control strategies, represented by different colors in the diagram.

[0147] To simplify operation and improve processing efficiency, this embodiment further determines the light intensity threshold corresponding to each temperature threshold based on the correspondence between light intensity values ​​and temperature values, thereby obtaining at least one preset light intensity threshold and multiple intervals divided by the at least one preset light intensity threshold. Each interval corresponds to a temperature range, and each interval corresponds to a temperature adjustment strategy. For example, a first light intensity threshold is obtained based on a temperature threshold of 100℃ and the correspondence between light intensity values ​​and temperature values; a second light intensity threshold is obtained based on a temperature threshold of 150℃ and the correspondence between light intensity values ​​and temperature values. Therefore, when determining the temperature adjustment strategy for grinding the wafer in the current wafer thinning equipment based on the light intensity value, the light intensity value is directly compared with the preset light intensity threshold to determine the interval to which the light intensity value belongs, and the temperature adjustment strategy can be further determined based on the determined interval. This process eliminates the need to convert the determined light intensity value into a temperature value each time and then determine the temperature adjustment strategy based on the temperature value, making the operation of this application simpler and the decision-making process for the temperature adjustment strategy faster and more timely, which helps to improve the accuracy of wafer thinning processing.

[0148] In one embodiment, the correspondence between temperature and light intensity values ​​is related to the pre-factor and the excitation energy level of the nanoparticles (e.g., middle The light intensity is related to the excitation energy level of the ions and the Boltzmann constant. In one embodiment, the light intensity value is positively correlated with the temperature value, the pre-factor, and the Boltzmann constant, and negatively correlated with the excitation energy level of the nanoparticles. For example, one relationship between the light intensity value and the temperature value is expressed as follows:

[0149]

[0150] in, I(T) Indicates the light intensity value; I initial Indicates pre-factor; E a This represents the excitation energy level of nanoparticles (e.g., The excitation energy levels of the ions are in the range of 1.8–2.2 eV. k Represents the Boltzmann constant; T This indicates the temperature value.

[0151] like Figure 7 The method for determining a light intensity threshold, as shown in one embodiment of this application, includes:

[0152] S71, Obtain the temperature threshold;

[0153] Temperature thresholds can be set as needed. If a more refined temperature adjustment strategy is required to differentiate between different temperature ranges, multiple temperature thresholds can be set. In this embodiment, two temperature thresholds are used as an example, including 100°C and 150°C.

[0154] S72. Based on the correspondence between temperature value and light intensity value, determine the light intensity threshold corresponding to the temperature threshold;

[0155] In one embodiment, a temperature threshold can be input into the above expression to obtain the output light intensity threshold.

[0156] In one embodiment, determining the temperature regulation strategy for grinding the wafer in the current wafer thinning equipment based on a range includes:

[0157] In response to the light intensity value being within the first range (corresponding to the first temperature range), a first temperature regulation strategy is adopted, including: adjusting the coolant flow rate to a preset initial flow rate and controlling the feed rate to a preset initial feed rate. That is, the default cooling parameters and feed rate are used within the first range.

[0158] In response to the light intensity value falling within the second range (corresponding to the second temperature range), a second temperature regulation strategy is adopted, including increasing the initial flow rate by a first percentage. That is, the second range corresponds to a higher temperature range than the first range, requiring a further increase in cooling intensity based on the cooling strategy corresponding to the first range, for example, increasing the initial coolant flow rate by 20%.

[0159] In response to the light intensity value falling within the third range (corresponding to the third temperature range), a third temperature regulation strategy is adopted, including: increasing the initial coolant flow rate by a second percentage, and controlling the feed rate to decrease by a predetermined percentage from the initial feed rate. In other words, the third range corresponds to a higher temperature range than the second range, requiring a further increase in cooling intensity based on the cooling strategy corresponding to the second range. For example, increasing the initial coolant flow rate by 50% and decreasing the initial feed rate of the feed component by 30%.

[0160] The embodiments of this application can use different cooling parameters in different ranges. Compared with the fixed cooling parameters used in traditional cooling measures, it can more accurately control the coolant flow rate and cooling effect, and avoid the problems of coolant waste or insufficient cooling.

[0161] It is understood that the above-mentioned increases in coolant flow rate and decreases in feed rate are merely examples, and different values ​​can be set as needed.

[0162] Figure 4 Step S42 can be executed once for each output light intensity value in step S41. The light intensity value output in step S41 can be the average of multiple light intensity values. Therefore, step S42 determines the temperature adjustment strategy for grinding the wafer in the current wafer thinning equipment based on the average of the light intensity values.

[0163] The embodiments of this application can determine the temperature adjustment strategy for grinding wafers in the current wafer thinning equipment based on the real-time output light intensity value, so as to promptly determine whether to stop or adjust the cooling measures.

[0164] To avoid the wafer temperature becoming unstable and rising again if the wafer temperature temporarily drops after enhanced cooling when the light intensity value is in the second or third range, the method in this application embodiment further includes:

[0165] In response to a change in the light intensity range of two consecutive determined light intensity values, including a change from a second or third range to a first range, and subsequent light intensity values ​​determined for a preset number of times all falling within the first range, the temperature adjustment strategy is adjusted to the first temperature adjustment strategy corresponding to the first range. For example, if the first output light intensity value belongs to the second range, the second output light intensity value belongs to the first range, and the third to fifth output light intensity values ​​all belong to the first range, then the temperature adjustment strategy for the current wafer thinning equipment's wafer grinding in the second to fourth times will be the temperature adjustment strategy corresponding to the second range, and the temperature adjustment strategy for the current wafer thinning equipment's wafer grinding in the fifth time will be the temperature adjustment strategy corresponding to the first range. It is understood that the preset number of times can be set as needed, for example, to different values ​​such as 2, 3, 4, or 5. This application can control the frequency of adjusting the temperature adjustment strategy by setting the value of the preset number of times.

[0166] In this embodiment, when the light intensity value drops back to the first range, the cooling measures will not be immediately stopped or adjusted. Instead, the temperature regulation strategy will only be adjusted to the first temperature regulation strategy corresponding to the first range after multiple determined light intensity values ​​(average values) have all fallen within the first range. This means that the cooling parameters will be reverted to the initial coolant flow rate and the feed rate will be adjusted back to the initial feed rate. This prevents the wafer temperature from becoming unstable and rising again due to an immediate stop or adjustment of the cooling measures when the wafer temperature temporarily drops due to enhanced cooling measures. This avoids the situation where repeated adjustments to the temperature regulation strategy would affect the wafer grinding accuracy.

[0167] To further understand this plan, please refer to Figure 8 The diagram shown is a flowchart of a specific embodiment of the thinning method of this application. In this embodiment, the nanoparticles are... The data collector is a photoelectric sensor, the coolant is water, the first light intensity threshold is I0, and the second light intensity threshold is I1. After grinding begins, grinding heat is generated in the grinding wheel. The light emission is triggered by heat, and a photoelectric sensor collects the light signal, converting it into a voltage signal V and outputting it to the controller. The controller determines the temperature regulation strategy based on the intensity of the light signal, specifically including the following steps:

[0168] S801. Determine the light intensity value I based on V t ;

[0169] In this step, based on the received voltage signal V and according to the preset calibration curve (i.e., the voltage-light intensity correspondence), the corresponding real-time light intensity value I is calculated t , and this step realizes the accurate mapping from the electrical signal to the physical quantity.

[0170] S802. Compare I t with I0 and I1 respectively;

[0171] In this step, the calculated light intensity value I t is logically compared with the two preset thresholds I0 and I1 to determine the interval to which the current grinding heat state belongs, and branches to the corresponding control steps according to the judgment result, where:

[0172] If I t < I0, it indicates that the grinding temperature is in the safe and low-temperature normal range, and the process enters S803.

[0173] If I0 ≤ I t < I1, it indicates that the grinding temperature has exceeded the safety baseline and entered the warning interval, and the process enters S804.

[0174] If I t ≥ I1, it indicates that the grinding temperature is too high and has entered the dangerous interval, and there is a risk of thermal damage, and the process immediately enters S805.

[0175] S803. Adopt the default grinding parameters and cooling parameters;

[0176] In this step, when the light intensity value is in the first interval, it is determined that the current heat load is low, and the first temperature adjustment strategy is executed. There is no need to start the enhanced cooling or speed reduction measures, so the system maintains all default grinding parameters, that is:

[0177] The cooling system supplies cooling water according to the preset initial flow rate;

[0178] The feeding component runs at the preset initial feeding speed.

[0179] This strategy兼顾了生产效率与资源节约 while ensuring the processing quality.

[0180] S804. Increase the cooling water flow rate by the first ratio;

[0181] This means increasing the cooling water flow rate by a certain percentage, such as 20%, based on the default cooling parameters. This step initiates a preventative temperature control strategy when the current light intensity value is in the second range. Its core principle is to increase cooling intensity to suppress temperature rise. Specifically, it increases the flow rate by 20% based on the preset initial flow rate. This instruction can be sent to the coolant flow control device (such as a variable frequency water pump). By increasing the flow rate and velocity, it enhances heat exchange efficiency, aiming to stabilize the temperature back within a safe range.

[0182] During this stage, the feed rate is usually kept constant to observe the cooling effect and avoid unnecessary efficiency loss.

[0183] S805, Increase the second proportional cooling water flow rate and reduce the predetermined proportional feed rate.

[0184] This means increasing the cooling water flow rate by 50% based on the default cooling parameters, and reducing the feed rate by 30% based on the preset initial feed rate.

[0185] This step involves initiating the highest level of protective intervention when the current light intensity value reaches the danger zone. This involves a powerful two-pronged approach: significantly increasing the flow rate (e.g., by 50%) from the preset initial flow rate to maximize cooling and urgently reduce the temperature of the grinding zone. Simultaneously, reducing the feed rate by 30% from the preset initial feed rate directly decreases the grinding speed, significantly reducing grinding heat generation at its source.

[0186] The core objective of this strategy is to quickly eliminate the risk of thermal overload, even at the cost of temporarily sacrificing efficiency, and to completely avoid irreversible thermal defects such as wafer warping, burning, or microcracks, thereby ensuring the final yield of the product.

[0187] During the grinding process and the cooling process using different cooling parameters, the data acquisition unit will also collect optical signals at a preset sampling frequency to monitor the grinding thermal changes in real time, thereby adjusting the temperature adjustment strategy to avoid wafer thermal damage and coolant waste.

[0188] To verify the effectiveness of this application, the inventors conducted multiple experiments to compare the thinning method of this application with traditional thinning methods. The traditional thinning method uses a conventional grinding wheel and a fixed cooling water flow rate of 5 L / min. The thinning method of this application uses a grinding wheel with added nanoparticles and dynamically adjusts the cooling water flow rate within the range of 3-4.5 L / min. The comparison of the process effects and characteristics is shown in Tables 1 and 2.

[0189] Table 1 Comparison of Grinding Wheel Process Effects

[0190]

[0191] Table 2 Comparison of Grinding Wheel Performance

[0192]

[0193] The wafer thinning method of this application obtains the light intensity value corresponding to the optical signal during the wafer grinding process of the wafer thinning equipment, and then determines the temperature regulation strategy of the current wafer thinning equipment model wafer based on the light intensity value. This application utilizes the thermoluminescence of nanoparticles in the grinding wheel block, which excites light signals of different intensities due to different grinding heat during the wafer grinding process. Therefore, the temperature regulation strategy of the wafer thinning equipment model wafer can be determined according to the different light intensity values. This method can judge the grinding heat based on the light intensity value, effectively improving the accuracy of grinding heat monitoring in the wafer grinding process. This allows for timely and effective temperature control measures based on accurate grinding heat, avoiding defects such as warping and burning of the wafer due to excessive temperature, and improving wafer grinding accuracy and yield. At the same time, because the accuracy of grinding heat monitoring in the wafer thinning process is improved, more accurate temperature control measures can be taken, avoiding problems such as coolant waste and insufficient cooling.

[0194] This application embodiment adds nanoparticles to the grinding wheel block, utilizing the interfacial stress-induced effect to achieve lattice dislocation pinning strengthening, thereby enhancing the toughness and bonding strength of the grinding wheel block. On the one hand, this can improve the service life of the grinding wheel and reduce the frequency of grinding wheel replacement in wafer thinning equipment. On the other hand, it can also reduce abrasive grain breakage and shedding, improve grinding stability, and thus achieve the effect of improving wafer grinding accuracy and yield.

[0195] Reference Figure 9 The diagram shown is a structural block diagram of a thinning device 50 provided in one embodiment of this application, comprising:

[0196] The light intensity value acquisition unit 51 is used to acquire the light intensity value corresponding to the light signal of the wafer thinning equipment model wafer process; the light signal is emitted by nanoparticles in the grinding wheel block under the heat of grinding.

[0197] The strategy determination unit 52 is used to determine the temperature regulation strategy of the current wafer thinning equipment model wafer based on the light intensity value.

[0198] In one embodiment, the strategy determination unit 52 further includes:

[0199] The first subunit (not shown in the figure) is used to compare the light intensity value with a preset light intensity threshold to determine the range to which the light intensity value belongs; the preset light intensity threshold is determined by a preset temperature threshold and the correspondence between temperature value and light intensity value;

[0200] The second sub-unit (not shown in the figure) is used to determine the temperature regulation strategy for grinding the wafer in the current wafer thinning equipment based on the interval.

[0201] In one embodiment, the second subunit determines the temperature regulation strategy for grinding the wafer in the current wafer thinning equipment based on the light intensity range, including:

[0202] In response to the light intensity value being in the first range, a first temperature regulation strategy is adopted, including: adjusting the coolant flow rate to a preset initial flow rate and controlling the feed rate to a preset initial feed rate;

[0203] In response to the light intensity value being in the second range, a second temperature adjustment strategy is adopted, including: increasing the initial flow rate by a first proportion; and

[0204] In response to the light intensity value being in the third range, a third temperature regulation strategy is adopted, including: increasing the second proportion based on the initial flow rate, and controlling the feed rate to decrease by a predetermined proportion based on the initial feed rate.

[0205] In one embodiment, the strategy determination unit 52 is further configured to:

[0206] In response to a change in the interval to which two consecutive determined light intensity values ​​belong, including: changing from the second or third interval to the first interval, and subsequent consecutive preset numbers of values ​​are all within the first interval; the temperature adjustment strategy is adjusted to the first temperature adjustment strategy corresponding to the first interval.

[0207] In one embodiment, the light intensity value acquisition unit 51 is specifically used for:

[0208] Obtain the average of the light intensity values ​​determined by a specified number of consecutive tests.

[0209] The strategy determination unit 52 is specifically used to determine the temperature regulation strategy of the current wafer thinning equipment model wafer based on the mean value of light intensity.

[0210] The further functions of the thinning device in this embodiment refer to the thinning method in the embodiment of this application, and will not be repeated here.

[0211] See Figure 10 , Figure 10 This is a schematic block diagram of an electronic device provided according to an embodiment of this application. Figure 10The electronic device 600 in this embodiment may include one or more processors 601, one or more input devices 602, one or more output devices 603, and one or more memories 604. The processors 601, input devices 602, output devices 603, and memories 604 communicate with each other via a communication bus 605. The memory 604 stores computer programs, including program instructions. The processor 601 executes the program instructions stored in the memory 604. The processor 601 is configured to invoke the program instructions to perform the functions of the units in the above-described device embodiments, for example... Figure 9 The functions of the light intensity value acquisition unit 51 and the strategy determination unit 52 are shown.

[0212] It should be understood that, in the embodiments of this application, the processor 601 may be a central processing unit, and the processor may also be other general-purpose processors, digital signal processors, application-specific integrated circuits, etc.

[0213] Input device 602 may include a touchpad, etc., and output device 603 may include a display, speaker, etc.

[0214] The memory 604 may include read-only memory and random access memory, and provides instructions and data to the processor 601. A portion of the memory 604 may also include non-volatile random access memory.

[0215] In specific implementations, the processor 601, input device 602, and output device 603 described in the embodiments of this application can execute the implementation methods described in the thinning method provided in the embodiments of this application. They can also execute the implementation methods of the electronic devices described in the embodiments of this application, which will not be elaborated further here.

[0216] In another embodiment of this application, a computer-readable storage medium is provided. This computer-readable storage medium stores a computer program, which includes program instructions. When executed by a processor, the program instructions implement all or part of the processes in the methods described above. Alternatively, the computer program can instruct related hardware to perform these processes. The computer-readable medium may include any entity or device capable of carrying computer program code, such as a USB flash drive, a portable hard drive, a computer memory, or a read-only memory.

[0217] The computer-readable storage medium can be an internal storage unit of the electronic device in any of the foregoing embodiments, such as a hard disk or memory of the electronic device. The computer-readable storage medium can also be an external storage device of the electronic device, such as a plug-in hard disk, smart memory card, etc., provided on the electronic device.

[0218] This application provides a computer program product, which includes computer-executable instructions or a computer program. The computer-executable instructions or computer program are stored in a computer-readable storage medium. The processor of an electronic device reads the computer-executable instructions from the computer-readable storage medium and executes the computer-executable instructions, causing the electronic device to perform the implementation described in the thinning method provided in this application.

[0219] It should be noted that, depending on the implementation needs, the various components / steps described in the embodiments of this application can be broken down into more components / steps, or two or more components / steps or parts of the operation of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of this application.

[0220] 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. A wafer thinning equipment, characterized in that, include: Grinding device, adsorption platform, collector and controller, The adsorption platform is used to support the wafer and drive the wafer to rotate. The grinding device is ellipsively positioned above the adsorption platform, and its lower part has a grinding wheel for grinding wafers; the grinding wheel includes a grinding block, the grinding block has nanoparticles, the nanoparticles have thermoluminescence properties, and are used to emit light signals of different intensities under different grinding thermal excitations; the nanoparticles are composed of lanthanide metal oxides. The collector is used to collect the optical signal; The controller is electrically connected to the collector and is used to determine the light intensity value corresponding to the light signal, and generate a temperature regulation strategy for grinding the wafer based on the light intensity value, including: controlling the coolant flow rate and adjusting the feed speed of the feed component according to the range of the light intensity value.

2. The wafer thinning equipment according to claim 1, characterized in that, The grinding block comprises diamond abrasive grains with nanoparticles loaded on its surface.

3. The wafer thinning equipment according to claim 1, characterized in that, The nanoparticles include one or more of europium oxide, cerium oxide, gadolinium oxide, and samarium oxide.

4. The wafer thinning apparatus according to any one of claims 1 to 3, characterized in that, The grinding apparatus includes: A feeding component is disposed above the adsorption platform and moves up and down relative to it. The feeding component is electrically connected to the controller, which is configured to control the feeding speed of the feeding component under different temperature regulation strategies. A rotating shaft is driven and raised / lowered by the feed assembly, and the grinding wheel is connected to the lower end of the rotating shaft.

5. The wafer thinning equipment according to claim 4, characterized in that, The controller includes: A comparator is used to compare the light intensity value with a preset light intensity threshold to determine the range to which the light intensity value belongs, so as to determine the temperature adjustment strategy for grinding the wafer in the current wafer thinning equipment based on the range; the preset light intensity threshold is determined by a preset temperature threshold and the correspondence between temperature value and light intensity value.

6. The wafer thinning equipment according to claim 5, characterized in that, The controller also includes: The first actuator is electrically connected to the comparator and the coolant flow rate regulating device, and is used to control the coolant flow rate according to the range of the light intensity value: if the light intensity value is in the first range, the coolant flow rate is adjusted to the preset initial flow rate; if the light intensity value is in the second range, the initial flow rate is increased by a first proportion; if the light intensity value is in the third range, the initial flow rate is increased by a second proportion. The second actuator, electrically connected to the comparator and the feed assembly, is used to adjust the feed speed according to the range to which the light intensity value belongs: if the light intensity value is in the first range, the feed speed is controlled to be a preset initial feed speed; if the light intensity value is in the third range, the feed speed is controlled to be reduced by a predetermined percentage based on the initial feed speed.

7. A thinning method, characterized in that, Includes the following steps: The light intensity value corresponding to the light signal during the wafer grinding process of the wafer thinning equipment is obtained; the light signal is emitted by nanoparticles in the grinding wheel block under the thermal excitation of grinding; the composition of the nanoparticles is lanthanide metal oxide; The temperature regulation strategy for grinding the wafer in the current wafer thinning equipment is determined based on the light intensity value, including: controlling the coolant flow rate and adjusting the feed speed of the feed component according to the range of the light intensity value.

8. The thinning method according to claim 7, characterized in that, The temperature regulation strategy for grinding wafers in the current wafer thinning equipment based on the light intensity value includes: The light intensity value is compared with a preset light intensity threshold to determine the range to which the light intensity value belongs; the preset light intensity threshold is determined by a preset temperature threshold and the correspondence between temperature value and light intensity value; The temperature regulation strategy for grinding wafers in the current wafer thinning equipment is determined based on the range.

9. The thinning method according to claim 8, characterized in that, The temperature regulation strategy for grinding wafers in the current wafer thinning equipment based on the interval includes: In response to the light intensity value being in the first range, a first temperature regulation strategy is adopted, including: adjusting the coolant flow rate to a preset initial flow rate and controlling the feed rate to a preset initial feed rate; In response to the light intensity value being in the second range, a second temperature adjustment strategy is adopted, including: increasing the initial flow rate by a first proportion; and In response to the light intensity value being in the third range, a third temperature regulation strategy is adopted, including: increasing the second proportion based on the initial flow rate, and controlling the feed rate to decrease by a predetermined proportion based on the initial feed rate.

10. The thinning method according to claim 9, characterized in that, The method further includes: In response to a change in the interval to which two consecutive determined light intensity values ​​belong, the change includes: changing from the second interval or the third interval to the first interval, and the light intensity values ​​determined for a subsequent preset number of consecutive times are all within the first interval; The temperature regulation strategy is adjusted to the first temperature regulation strategy corresponding to the first interval.

11. The thinning method according to any one of claims 7 to 10, characterized in that, The method further includes: Obtain the average of light intensity values ​​determined by a specified number of consecutive iterations; The temperature regulation strategy for grinding wafers in the current wafer thinning equipment based on the light intensity value includes: The temperature control strategy for grinding wafers in the current wafer thinning equipment is determined based on the average value of the light intensity.

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