CN110539209A - processing method of thin plate-shaped sapphire wafer - Google Patents
processing method of thin plate-shaped sapphire wafer Download PDFInfo
- Publication number
- CN110539209A CN110539209A CN201910754849.0A CN201910754849A CN110539209A CN 110539209 A CN110539209 A CN 110539209A CN 201910754849 A CN201910754849 A CN 201910754849A CN 110539209 A CN110539209 A CN 110539209A
- Authority
- CN
- China
- Prior art keywords
- grinding disc
- grinding
- abrasive
- double
- sided
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
- B24B37/07—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool
- B24B37/08—Lapping machines or devices; Accessories designed for working plane surfaces characterised by the movement of the work or lapping tool for double side lapping
Abstract
the invention discloses a processing method of a thin plate-shaped sapphire wafer, which is characterized by comprising the following steps: the thin plate-shaped sapphire wafer is sequentially subjected to double-sided free abrasive grinding, double-sided fixed hard abrasive grinding disc rough grinding, double-sided fixed hard abrasive grinding disc fine grinding and double-sided fixed soft abrasive grinding disc mechanical chemical polishing treatment. The free abrasive double-sided grinding mainly reduces the waviness of the thin plate-shaped sapphire wafer and controls the flatness. The grinding pressure can be increased by grinding the double-sided fixed abrasive grinding disc, the material removal rate is improved, the controllability of the processing precision and the surface quality is high, and the processing efficiency is high. The mechanical chemical polishing of the fixed soft abrasive grinding disc can greatly improve the grinding and polishing efficiency of the wafer, avoid the great loss of the traditional silica sol polishing solution, reduce the cost and protect the environment. The invention can process and manufacture thin plate-shaped sapphire wafers with high precision, high quality and high efficiency.
Description
Technical Field
The invention belongs to the technical field of sapphire ultra-precision machining, and mainly relates to a machining method of a thin plate-shaped sapphire wafer.
background
Sapphire is a crystal of (alpha-Al 2O3) alumina, commonly known as corundum, and the lattice structure of the sapphire is a hexagonal lattice structure. The single crystal sapphire has excellent optical performance and chemical stability, high strength, high hardness, and good impact resistance and wear resistance, and can be widely applied to infrared optical materials, window materials of high-strength laser, high-temperature superconducting thin film wafers, LED substrate materials and the like. Single crystal sapphire has slow growth rate, low processing efficiency, and high cost compared to other types of crystalline materials, which severely limit the applications of sapphire wafers.
as shown in fig. 1, a conventional thin plate-shaped sapphire wafer is obtained by cutting a sapphire ingot in a fixed size by using a diamond multi-wire cutting technique, then performing free abrasive grinding, high-temperature chemical wet etching and single-side free diamond mechanical polishing on the cut wafer, and finally performing chemical mechanical polishing by using nano-silica sol. Because the single crystal sapphire belongs to a hard and brittle material, the diamond multi-wire cutting mode inevitably causes larger surface damage and deep saw marks, increases the removal amount and the processing time of subsequent grinding and corrosion, and is not beneficial to reducing the cost. Meanwhile, corrosion by strong acid and strong base causes certain environmental pollution, and the concept of green development is not met.
Conventional free abrasive grinding also has a number of disadvantages. The free abrasive grinding mode is adopted, and the requirement on the uniformity of the abrasive is high. When the abrasive particles are unevenly distributed and large abrasive particles participate in grinding, surface damage such as pit, chipping, crack, scratch and the like and sub-surface damage are easily caused, and the processing performance is unstable. In addition, the abrasive is in a free state, which limits the processing efficiency. The rotating speed of the grinding disc is too high, the grinding materials fly out under the centrifugal force, the utilization rate of the grinding materials is low, and the environmental pollution can be caused by improper treatment of waste liquid, so that the production cost is increased.
the technical deficiencies of the conventional CMP chemical mechanical polishing technique are mainly: the sapphire polishing machine has the advantages of low processing efficiency, low utilization rate of polishing solution, high polishing solution loss, increased sapphire processing cost, and environmental pollution caused by the discharge of the polishing solution and subsequent cleaning links. There is a need for improvements over conventional processes that address these issues.
the Edge-defined Film-Fed Growth (EFG) method is a new method for preparing thin plate-shaped sapphire wafers, and has the characteristics of short Growth period, continuous feeding, capability of preparing wafers with specific shapes and sizes, no damage layer, capability of simplifying subsequent processing procedures, effective cost reduction and the like compared with a diamond multi-wire cutting technology. However, the mold guiding method is based on the principle that the narrow gap of the mold has a capillary effect on the melt, so that the surface of the molded wafer has a large waviness due to the drawing of the capillary effect and the extrusion of the mold, the surface has a hilly-shaped undulating appearance, and the surface shape is poor. Therefore, a new process needs to be developed for the surface characteristics of sapphire wafers prepared by the mold-guiding method, the surface shape is optimized, the processing efficiency is improved, and an ultra-smooth surface with excellent dimensional precision, geometric precision and no processing deterioration layer is obtained.
disclosure of Invention
Based on the problems in the background art, the invention provides a processing method of a thin plate-shaped sapphire wafer, which is simple in process, green, environment-friendly, efficient and low in damage.
The technical means adopted by the invention are as follows:
A processing method of a thin plate-shaped sapphire wafer comprises the following steps: the thin plate-shaped sapphire wafer is sequentially subjected to double-sided free abrasive grinding, double-sided fixed hard abrasive grinding disc rough grinding, double-sided fixed hard abrasive grinding disc fine grinding and double-sided fixed soft abrasive grinding disc mechanical chemical polishing treatment.
The double-sided free abrasive grinding adopts an upper grinding disc and a lower grinding disc to grind the upper surface and the lower surface of the thin plate-shaped sapphire wafer simultaneously and respectively so as to reduce the waviness and ensure the flatness;
the grinding liquid is prepared by fully mixing hard grinding materials with the granularity of W14-W20 and deionized water according to the mass ratio of 1: 15-1: 20 and uniformly stirring;
The rotating speed of the upper grinding disc is 15-20r/min, and the rotating speed of the lower grinding disc is 30-35 r/min;
the grinding pressure of the upper grinding disc and the lower grinding disc is 0.05-0.08 MPa;
The grinding liquid flows to the upper surface and the lower surface of the thin plate-shaped sapphire wafer from the flow channels in the upper grinding disc and the lower grinding disc, and the flow rate is 40-50 ml/min;
the grinding time of the double-sided free abrasive is 25-30 min.
the hard abrasive is one or more of diamond, SiC and B4C;
The upper grinding disc and the lower grinding disc are made of gray cast iron or brass.
The double-sided free abrasive grinding aims at removing hillock-shaped bulges on the upper surface and the lower surface of a thin plate-shaped sapphire wafer prepared by a die guide method, greatly reducing waviness, optimizing surface shape, ensuring flatness to be less than 10 mu m, avoiding the phenomenon of stress concentration breakage caused by increasing grinding pressure in the next process and improving yield.
the double-sided fixed hard abrasive grinding disc rough grinding adopts an upper rough grinding disc and a lower rough grinding disc to simultaneously and respectively grind the upper surface and the lower surface of a thin plate-shaped sapphire wafer ground by double-sided free abrasive;
The upper rough grinding disc and the lower rough grinding disc are formed by sintering a bonding agent and hard abrasive with the grain size of W10-W14;
the rotating speed of the upper coarse grinding disc is 50-60r/min, and the rotating speed of the lower coarse grinding disc is 100-;
The grinding pressure of the upper coarse grinding disc and the lower coarse grinding disc is 0.25-0.3 MPa;
The grinding time of the rough grinding of the double-sided consolidation hard grinding disc is 15-20min, and the cooling mode is continuous cooling by adopting deionized water.
the grinding disc abrasive concentration of the upper coarse grinding disc and the lower coarse grinding disc is 100%;
the hard abrasive is one or a combination of more of diamond, CBN and SiC;
the bonding agent is a ceramic bonding agent, a ceramic resin composite bonding agent or a resin bonding agent;
The manufacturing process of the upper coarse grinding disc and the lower coarse grinding disc is as follows:
Placing hard abrasive with the granularity of W10-W14 into a mortar for mixing, gradually dripping a temporary binder methyl cellulose aqueous solution or a sodium carboxymethylcellulose aqueous solution with the concentration of 0.3-0.4% into the mortar until the hard abrasive is wetted, then adding mixed powder of a binding agent and the paste powder, and fully stirring for 15-20min until the binding agent can fully wrap the hard abrasive to obtain mixed powder; pressing the mixed powder into a mold, keeping the pressure at 60-80 MPa for 4-5 min; and then, placing the mixture into a sintering furnace for sintering at 650-780 ℃, wherein the whole sintering process is protected under the atmosphere of N2.
the ceramic bond is B2O3-Al2O3-SiO2 series ceramic bond.
the purpose of the rough grinding of the double-sided consolidation hard grinding material grinding disc is to increase grinding pressure and grinding rotating speed, increase the removal amount of sapphire wafers, improve the material removal rate, improve the processing efficiency, have high grinding material utilization rate and strong surface quality controllability, and solve the problem that grinding fluid is difficult to recycle. The roughness of the upper surface and the lower surface of the thin plate-shaped sapphire wafer after the rough grinding of the double-sided bonded hard grinding disc is 450-550 nm.
The double-sided consolidation hard abrasive grinding disc is used for fine grinding, and an upper fine grinding disc and a lower fine grinding disc are simultaneously and respectively used for grinding the upper surface and the lower surface of the thin plate-shaped sapphire wafer which is roughly ground by the double-sided consolidation hard abrasive grinding disc;
the upper fine grinding disc and the lower fine grinding disc are formed by sintering a bonding agent and hard abrasive materials with the granularity of W5-W7;
the rotating speed of the upper fine grinding disc is 60-70r/min, and the rotating speed of the lower fine grinding disc is 120-;
the grinding pressure of the upper grinding disc and the lower grinding disc is 0.25-0.3 MPa;
The grinding time of the fine grinding of the double-sided consolidation hard grinding disc is 100-120min, and the cooling mode is continuous cooling by adopting deionized water.
The grinding disc abrasive concentration of the upper grinding disc and the lower grinding disc is 100%;
The hard abrasive is one or a combination of more of diamond, CBN and SiC;
the bonding agent is a ceramic bonding agent, a ceramic resin composite bonding agent or a resin bonding agent;
The manufacturing process of the upper grinding disc and the lower grinding disc is as follows:
placing hard abrasive with the granularity of W5-W7 into a mortar for mixing, gradually dripping a temporary binder methyl cellulose aqueous solution or a sodium carboxymethylcellulose aqueous solution with the concentration of 0.3-0.4% into the mortar until the hard abrasive is wetted, then adding mixed powder of a binding agent and the paste powder, and fully stirring for 15-20min until the binding agent can fully wrap the hard abrasive to obtain mixed powder; pressing the mixed powder into a mold, keeping the pressure at 60-80 MPa for 4-5 min; and then, placing the mixture into a sintering furnace for sintering at 650-780 ℃, wherein the whole sintering process is protected under the atmosphere of N2.
The ceramic bond is B2O3-Al2O3-SiO2 series ceramic bond.
The purpose of the fine grinding of the double-sided consolidation hard grinding material grinding disc is to keep a certain material removal rate, reduce the depth of a processed subsurface damage layer and improve the surface type precision and the surface quality of a thin plate-shaped sapphire wafer. The roughness of the upper surface and the lower surface of the thin plate-shaped sapphire wafer after the double-sided fixed hard abrasive grinding disc is finely ground is 40-50 nm.
The double-sided fixed soft abrasive grinding disc mechanical chemical polishing adopts an upper fixed soft abrasive grinding disc and a lower fixed soft abrasive grinding disc to simultaneously and respectively polish the upper surface and the lower surface of a thin plate-shaped sapphire wafer finely ground by a double-sided fixed hard abrasive grinding disc;
the upper fixed soft abrasive grinding disc and the lower fixed soft abrasive grinding disc are formed by solidifying a bonding agent and a soft abrasive with the granularity of W1-W3;
the rotating speed of the upper fixed soft abrasive grinding disc is 45-55r/min, and the rotating speed of the lower fixed soft abrasive grinding disc is 90-110 r/min;
the polishing pressure of the upper fixed soft abrasive grinding disc and the lower fixed soft abrasive grinding disc is 0.5-0.6 MPa;
The polishing time of the mechanical chemical polishing of the double-sided fixed soft abrasive grinding disc is 50-70min, and the cooling mode is continuous cooling by adopting deionized water.
The soft abrasive is one or a combination of more of SiO2, CeO2, Fe2O3 and alpha-Al 2O 3;
The binding agent is a magnesium oxychloride binding agent;
the manufacturing process of the upper fixed soft abrasive grinding disc and the lower fixed soft abrasive grinding disc is as follows:
Screening MgO by using a sieve with the specification of 300#, and drying the MgO and a soft abrasive with the particle size of W1-W3 in a blast oven for 60min at the temperature of 40 ℃ to obtain a dry mixture; preparing a MgCl2 solution with the mass fraction of 70-80%, mixing with the dry mixture, ensuring that the molar ratio of MgO/MgCl2 is 5:1, stirring the mixture evenly, pouring the mixture into a mold, covering a pressing plate on the mold, and curing the mixture at normal temperature (25 ℃) for more than 2 weeks; the fully cured abrasive block was bonded to the cast iron substrate of the upper and lower bonded soft abrasive discs with 504AB glue and the upper and lower bonded soft abrasive discs were dressed using electroplated diamond dressing rings.
in this process, the upper and lower fixed soft abrasive discs are dressed when they are first used or re-clamped. The method not only can expose the soft abrasive covered by the bonding agent and ensure the grinding effect, but also ensures the surface shape precision of the whole upper fixed soft abrasive grinding disc and the whole lower fixed soft abrasive grinding disc, thereby ensuring the surface shape precision of the thin plate-shaped sapphire wafer after grinding and polishing.
the double-sided fixed soft abrasive grinding disc mechanical chemical polishing aims at performing solid phase chemical reaction on the surface of a thin plate-shaped sapphire wafer by using a soft abrasive and a bonding agent to generate a thin solid phase chemical reaction passivation layer, reducing the hardness of a surface layer, continuously scratching the fixed soft abrasive grinding disc to remove the passivation layer, removing a 1-2 mu m damage layer caused by fine grinding of the double-sided fixed hard abrasive grinding disc, ensuring that the hardness of the soft abrasive is softer than that of a material and cannot cause new physical damage to the surface of the thin plate-shaped sapphire wafer, and achieving the effects of nano-scale roughness (0.25-0.4nm) and highly flattened nondestructive polishing. The thin plate-shaped sapphire wafer is polished for about 60min by adopting a fixed grinding disc made of a magnesium oxychloride bonding agent and a soft abrasive and the polishing process parameters, so that an ultra-smooth surface with the surface roughness of 0.25-0.4nm can be obtained, and the CMP polishing processing effect can be achieved.
the invention has the following advantages:
the characteristics of small grinding pressure, small material removal amount and good surface shape control of free grinding material double-sided grinding are utilized, the hillock fluctuation morphology of the surface of the thin plate-shaped sapphire wafer is improved, the waviness is greatly reduced, and the flatness is ensured. In the whole set of process, the free abrasive double-side grinding is the main process for ensuring the wafer flatness.
the fixed abrasive grinding technology has the biggest characteristic of being capable of remarkably improving the material removal rate and the surface quality of a processed workpiece, and compared with the free abrasive grinding technology, the fixed abrasive grinding technology has the advantages that the surface type precision of processing is better, the abrasive utilization rate is higher, the processing precision and the surface quality are higher in controllability, the processing efficiency is higher, the fixed abrasive grinding processing does not need to add abrasive and turbid liquid, deionized water can be directly used as grinding liquid, and the processing is more environment-friendly.
the mechanical chemical polishing technology of the fixed soft abrasive grinding disc can greatly improve the grinding and polishing efficiency of the wafer and improve the utilization rate of the abrasive on the premise of ensuring the polishing quality, can directly use deionized water as polishing solution, avoids a large amount of loss of the traditional CMP silica sol polishing solution, reduces the cost and is green and environment-friendly.
The invention can process and manufacture thin plate-shaped sapphire wafers with high precision, high quality and high efficiency.
for the above reasons, the present invention can be widely applied to the fields of ultra-precision machining and the like.
Drawings
in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a process flow of a conventional process for preparing and processing a thin plate-shaped sapphire wafer.
fig. 2 is a process flow of preparing a processed thin plate-shaped sapphire wafer in example 1 of the present invention.
fig. 3 is a process flow of preparing a processed thin plate-shaped sapphire wafer in example 2 of the present invention.
Detailed Description
in order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
as shown in fig. 2, a method for processing a thin plate-like sapphire wafer includes the steps of:
s1, double-sided free abrasive grinding:
Fully mixing the diamond powder of W20 with deionized water according to the mass ratio of 1: 15-1: 20, continuously stirring by using a magnetic stirrer, and keeping the suspension state to obtain a grinding fluid; the upper grinding disc and the lower grinding disc are made of HT250 gray cast iron. The method comprises the following steps that a thin plate-shaped sapphire wafer is placed in a planetary wheel groove of a constant-pressure double-sided grinding machine, grinding liquid is continuously injected by a peristaltic pump and an internal flow channel of the grinding machine, and the grinding liquid flows to the upper surface and the lower surface of the thin plate-shaped sapphire wafer from the flow channel inside an upper grinding disc and a lower grinding disc; the rotating speed of the upper grinding disc is 15r/min, the rotating speed of the lower grinding disc is 30r/min, the grinding pressure is 0.05MPa, the flow of the grinding fluid is controlled at 45ml/min, and the grinding time is 25 min. The planeness of the thin plate-shaped sapphire wafer after grinding is less than 10 mu m;
S2, coarse grinding by using a double-sided consolidation hard grinding material grinding disc:
Firstly, sintering and consolidating an upper coarse grinding disc and a lower coarse grinding disc, selecting diamond micro powder with the granularity of W12 and green SiC with the same granularity, placing the diamond micro powder and the green SiC in a mortar, mixing, dropwise adding a temporary bonding agent methyl cellulose aqueous solution with the concentration of 0.3%, and wetting the whole hard grinding material; uniformly mixing B2O3-Al2O3-SiO2 series ceramic bond micro powder and the dextrin powder according to the mass ratio of 6: 1; fully mixing and stirring the hard abrasive and the bonding agent powder for 20min until the hard abrasive can be fully wrapped to obtain mixed powder; pressing the mixed powder into a die, keeping the pressure at 80MPa for 5 min; and (3) placing the mixture into a sintering furnace to be sintered for 120min at 750 ℃, wherein the whole sintering process is carried out under the protection of an N2 atmosphere. The sintered and finished upper and lower rough grinding discs were mounted in a constant pressure double side grinder with a disc abrasive concentration of 100%. And placing the thin plate-shaped sapphire wafer which is ground by the double-sided free grinding material into a planetary wheel groove of a constant-pressure double-sided grinding machine. The rotating speed of the upper coarse grinding disc is 50r/min, the rotating speed of the lower coarse grinding disc is 100r/min, the grinding pressure is 0.25MPa, and the grinding time is 15 min; continuously injecting deionized water by using a peristaltic pump for cooling; after coarse grinding, the surface roughness of the thin plate-shaped sapphire wafer is about 450 nm;
S3, fine grinding by a double-sided consolidation hard grinding material grinding disc:
Firstly, sintering and consolidating an upper grinding disc and a lower grinding disc, selecting diamond micro powder with the granularity of W5 and mixed powder of green SiC with the same granularity and B2O3-Al2O3-SiO2 series ceramic bond, sintering at high temperature, wherein the sintering process is similar to the step S2, installing the sintered and finished upper grinding disc and lower grinding disc into a constant-pressure double-sided grinding machine, wherein the grinding material concentration of the grinding disc is 100%, placing a thin plate-shaped sapphire wafer coarsely ground by a double-sided consolidation hard grinding disc into a planetary wheel groove of the constant-pressure double-sided grinding machine, the rotating speed of the upper grinding disc is 60r/min, the rotating speed of the lower grinding disc is 120r/min, the grinding pressure is 0.3MPa, the grinding time is 100min, continuously injecting deionized water into the grinding pump for cooling, and the surface roughness of the thin plate-shaped sapphire wafer after grinding is about 40 nm;
S4, mechanically and chemically polishing by using a double-sided fixed soft abrasive grinding disc:
Firstly, preparing an upper fixed soft abrasive grinding disc and a lower fixed soft abrasive grinding disc, screening MgO by using a screen with the specification of No. 300, selecting alpha-Al 2O3 abrasive with the particle size of W1 to be mixed with MgO powder according to the mass ratio of 1:1, blowing and drying for 60min at 40 ℃, preparing MgCl2 solution with the mass fraction of 75%, fully mixing the three to ensure that the molar ratio of MgO/MgCl2 is 5:1, stirring for 15min till the mixture is uniform, pouring the mixture into a mold, covering a pressing plate on the mold, and curing for more than 2 weeks at normal temperature (25 ℃); finally, uniformly bonding the fully cured grinding tool grinding blocks on the grinding disc cast iron matrixes of the upper fixed soft grinding material grinding disc and the lower fixed soft grinding material grinding disc by using 504AB glue; mounting the millstones of the upper fixed soft abrasive millstone and the lower fixed soft abrasive millstone into a constant-pressure double-sided grinder, and dressing the millstones of the upper fixed soft abrasive millstone and the lower fixed soft abrasive millstone by using an electroplating diamond dressing ring; the thin plate-shaped sapphire wafer finely ground by the double-sided fixed hard abrasive grinding disc is placed in a planetary wheel groove of a constant-pressure double-sided grinding machine, the rotating speed of an upper fixed soft abrasive grinding disc is 50r/min, the rotating speed of a lower fixed soft abrasive grinding disc is 100r/min, the polishing pressure is 0.5MPa, and the polishing time is 60 min. And continuously injecting deionized water by using a peristaltic pump for cooling. The ultra-smooth wafer surface with the surface roughness of about 0.3nm can be obtained after the mechanical chemical polishing of a double-sided fixed soft abrasive grinding disc.
The constant-pressure double-sided grinding machine in the embodiment adopts a BZ16B-8 type, the diameter of a grinding disc is about phi 1200mm, the number of the planetary wheels is 8, and the power is about 22 KW. Surface roughness measurements were performed using a Newview5022 model 3D surface profiler from Zygo, usa.
Example 2
as shown in fig. 3, a method for processing a thin plate-like sapphire wafer includes the steps of:
And S1, grinding by using a double-sided free abrasive.
fully mixing the SiC micropowder of W20 with deionized water according to the mass ratio of 1: 15-1: 20, continuously stirring by using a magnetic stirrer, and keeping the suspension state to obtain a grinding fluid; the upper grinding disc and the lower grinding disc are made of HT200 gray cast iron; the method comprises the following steps that a thin plate-shaped sapphire wafer is placed in a planetary wheel groove of a constant-pressure double-sided grinding machine, grinding liquid is continuously injected by a peristaltic pump and an internal flow channel of the grinding machine, and the grinding liquid flows to the upper surface and the lower surface of the thin plate-shaped sapphire wafer from the flow channel inside an upper grinding disc and a lower grinding disc; the rotating speed of the upper grinding disc is 10r/min, the rotating speed of the lower grinding disc is 25r/min, the grinding pressure is 0.03MPa, the flow of the grinding fluid is controlled at 40ml/min, and the grinding time is 30 min; the planeness of the thin plate-shaped sapphire wafer after grinding is less than 10 mu m;
s2, coarse grinding by using a double-sided consolidation hard grinding material grinding disc:
firstly, sintering and solidifying an upper coarse grinding disc and a lower coarse grinding disc, placing CBN micro powder with the granularity of W12 and green SiC with the same granularity in a mortar for mixing, dropwise adding a temporary bonding agent methyl cellulose aqueous solution with the concentration of 0.3%, wetting the whole hard grinding material, and uniformly mixing B2O3-Al2O3-SiO2 series ceramic bonding agent micro powder and dextrin powder according to the mass ratio of 6: 1; fully mixing and stirring the hard abrasive and the bonding agent powder for 20min until the hard abrasive can be fully wrapped to obtain mixed powder; pressing the mixed powder into a die, keeping the pressure at 80MPa for 5 min; and (3) placing the mixture into a sintering furnace to be sintered for 120min at 750 ℃, wherein the whole sintering process is carried out under the protection of an N2 atmosphere. The sintered and finished upper and lower rough grinding discs were mounted in a constant pressure double side grinder with a disc abrasive concentration of 100%. And placing the thin plate-shaped sapphire wafer which is ground by the double-sided free grinding material into a planetary wheel groove of a constant-pressure double-sided grinding machine. The rotating speed of the upper coarse grinding disc is 50r/min, the rotating speed of the lower coarse grinding disc is 100r/min, the grinding pressure is 0.3MPa, and the grinding time is 10 min; continuously injecting deionized water by using a peristaltic pump for cooling; after coarse grinding, the surface roughness of the thin plate-shaped sapphire wafer is about 500 nm;
S3, fine grinding by a double-sided consolidation hard grinding material grinding disc:
firstly, an upper grinding disc and a lower grinding disc are required to be sintered and consolidated, and CBN micro powder with the granularity of W5 and green SiC and B2O3-Al2O3-SiO2 series ceramic bond mixed powder with the same granularity are selected for high-temperature sintering. The sintering process is similar to the step S2, the sintered and finished upper fine grinding disc and lower fine grinding disc are installed in a constant-pressure double-sided grinding machine, the grinding concentration of the grinding disc is 100%, the thin plate-shaped sapphire wafer which is roughly ground by the double-sided consolidation hard grinding disc is placed in a planetary wheel groove of the constant-pressure double-sided grinding machine, the rotating speed of the upper fine grinding disc is 60r/min, the rotating speed of the lower fine grinding disc is 110r/min, the grinding pressure is 0.3MPa, and the grinding time is 120 min. And continuously injecting deionized water by using a peristaltic pump for cooling. After fine grinding, the surface roughness of the thin plate-shaped sapphire wafer is about 45 nm;
and S4, mechanically and chemically polishing by using a double-sided fixed soft abrasive grinding disc.
firstly, preparing an upper fixed soft abrasive grinding disc and a lower fixed soft abrasive grinding disc, screening MgO by using a screen with the specification of No. 300, selecting CeO2 abrasive with the particle size of W1 to be mixed with MgO powder according to the mass ratio of 1:1, blowing and drying for 60min at 40 ℃, preparing MgCl2 solution with the mass fraction of 75%, fully mixing the three, ensuring the molar ratio of MgO/MgCl2 to be 5:1, stirring for 15min to be uniform, pouring into a mold, covering a pressing plate on the mold, and curing at normal temperature (25 ℃) for more than 2 weeks; finally, uniformly bonding the fully cured grinding tool grinding blocks on the grinding disc cast iron matrixes of the upper fixed soft grinding material grinding disc and the lower fixed soft grinding material grinding disc by using 504AB glue; mounting the millstones of the upper fixed soft abrasive millstone and the lower fixed soft abrasive millstone into a constant-pressure double-sided grinder, and dressing the millstones of the upper fixed soft abrasive millstone and the lower fixed soft abrasive millstone by using an electroplating diamond dressing ring; placing the thin plate-shaped sapphire wafer finely ground by the double-sided consolidation hard grinding disc into a planetary wheel groove of a constant-pressure double-sided grinding machine; the rotating speed of the upper fixed soft abrasive grinding disc is 45r/min, the rotating speed of the lower fixed soft abrasive grinding disc is 90r/min, the polishing pressure is 0.5MPa, the polishing time is 70min, deionized water is continuously injected into the upper fixed soft abrasive grinding disc and cooled by a peristaltic pump, and the ultra-smooth wafer surface with the surface roughness of about 0.3nm can be obtained after the mechanical chemical polishing of the double-sided fixed soft abrasive grinding disc.
the constant-pressure double-sided grinding machine in the embodiment adopts a BZ13B-6 type, the diameter of a grinding disc is about phi 970mm, the number of the planetary wheels is 5, and the power is about 15 KW. Surface roughness measurements were performed using a Newview5022 model 3D surface profiler from Zygo, usa.
finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (9)
1. a processing method of a thin plate-shaped sapphire wafer is characterized by comprising the following steps: the thin plate-shaped sapphire wafer is sequentially subjected to double-sided free abrasive grinding, double-sided fixed hard abrasive grinding disc rough grinding, double-sided fixed hard abrasive grinding disc fine grinding and double-sided fixed soft abrasive grinding disc mechanical chemical polishing treatment.
2. The method according to claim 1, wherein the double-sided free abrasive lapping simultaneously and respectively grinds the upper and lower surfaces of the thin plate-shaped sapphire wafer by using an upper lapping disc and a lower lapping disc;
The double-sided free abrasive grinding adopts an upper grinding disc and a lower grinding disc to grind the upper surface and the lower surface of the thin plate-shaped sapphire wafer simultaneously and respectively;
the grinding liquid is prepared by fully mixing hard grinding materials with the granularity of W14-W20 and deionized water according to the mass ratio of 1: 15-1: 20 and uniformly stirring;
the rotating speed of the upper grinding disc is 15-20r/min, and the rotating speed of the lower grinding disc is 30-35 r/min;
the grinding pressure of the upper grinding disc and the lower grinding disc is 0.05-0.08 MPa;
The grinding liquid flows to the upper surface and the lower surface of the thin plate-shaped sapphire wafer from the flow channels in the upper grinding disc and the lower grinding disc, and the flow rate is 40-50 ml/min;
The grinding time of the double-sided free abrasive is 25-30 min.
3. the method of claim 2, wherein the hard abrasive is one or more of diamond, SiC, B4C in combination;
the upper grinding disc and the lower grinding disc are made of gray cast iron or brass.
4. the method of claim 1, wherein the double-sided consolidated hard abrasive disc rough grinding adopts an upper rough grinding disc and a lower rough grinding disc to grind the upper surface and the lower surface of the double-sided free abrasive ground thin plate-shaped sapphire wafer respectively at the same time;
the upper rough grinding disc and the lower rough grinding disc are formed by sintering a bonding agent and hard abrasive with the grain size of W10-W14;
the rotating speed of the upper coarse grinding disc is 50-60r/min, and the rotating speed of the lower coarse grinding disc is 100-;
the grinding pressure of the upper coarse grinding disc and the lower coarse grinding disc is 0.25-0.3 MPa;
the grinding time of the rough grinding of the double-sided consolidation hard grinding disc is 15-20min, and the cooling mode is continuous cooling by adopting deionized water.
5. the method of claim 4, wherein the upper and lower rough grinding discs have a disc abrasive concentration of 100%;
The hard abrasive is one or a combination of more of diamond, CBN and SiC;
the bonding agent is a ceramic bonding agent, a ceramic resin composite bonding agent or a resin bonding agent;
The manufacturing process of the upper coarse grinding disc and the lower coarse grinding disc is as follows:
Placing hard abrasive with the granularity of W10-W14 into a mortar for mixing, gradually dripping a temporary binder methyl cellulose aqueous solution or a sodium carboxymethylcellulose aqueous solution with the concentration of 0.3-0.4% into the mortar until the hard abrasive is wetted, then adding mixed powder of a binding agent and the paste powder, and fully stirring for 15-20min until the binding agent can fully wrap the hard abrasive to obtain mixed powder; pressing the mixed powder into a mold, keeping the pressure at 60-80 MPa for 4-5 min; and then, placing the mixture into a sintering furnace for sintering at 650-780 ℃, wherein the whole sintering process is protected under the atmosphere of N2.
6. the method of claim 1, wherein the double-sided consolidated hard abrasive disk finish grinding uses an upper finish grinding disk and a lower finish grinding disk to simultaneously and respectively grind the upper and lower surfaces of the thin plate-like sapphire wafer roughly ground by the double-sided consolidated hard abrasive disk;
The upper fine grinding disc and the lower fine grinding disc are formed by sintering a bonding agent and hard abrasive materials with the granularity of W5-W7;
The rotating speed of the upper fine grinding disc is 60-70r/min, and the rotating speed of the lower fine grinding disc is 120-;
The grinding pressure of the upper grinding disc and the lower grinding disc is 0.25-0.3 MPa;
the grinding time of the fine grinding of the double-sided consolidation hard grinding disc is 100-120min, and the cooling mode is continuous cooling by adopting deionized water.
7. The method of claim 6, wherein the upper and lower refiner discs have a disc abrasive concentration of 100%;
the hard abrasive is one or a combination of more of diamond, CBN and SiC;
the bonding agent is a ceramic bonding agent, a ceramic resin composite bonding agent or a resin bonding agent;
The manufacturing process of the upper grinding disc and the lower grinding disc is as follows:
placing hard abrasive with the granularity of W5-W7 into a mortar for mixing, gradually dripping a temporary binder methyl cellulose aqueous solution or a sodium carboxymethylcellulose aqueous solution with the concentration of 0.3-0.4% into the mortar until the hard abrasive is wetted, then adding mixed powder of a binding agent and the paste powder, and fully stirring for 15-20min until the binding agent can fully wrap the hard abrasive to obtain mixed powder; pressing the mixed powder into a mold, keeping the pressure at 60-80 MPa for 4-5 min; and then, placing the mixture into a sintering furnace for sintering at 650-780 ℃, wherein the whole sintering process is protected under the atmosphere of N2.
8. the method of claim 1, wherein the double-sided fixed soft abrasive grinding disc mechanical chemical polishing adopts an upper fixed soft abrasive grinding disc and a lower fixed soft abrasive grinding disc to simultaneously and respectively polish the upper surface and the lower surface of the thin plate-shaped sapphire wafer finely ground by a double-sided fixed hard abrasive grinding disc;
the upper fixed soft abrasive grinding disc and the lower fixed soft abrasive grinding disc are formed by solidifying a bonding agent and a soft abrasive with the granularity of W1-W3;
The rotating speed of the upper fixed soft abrasive grinding disc is 45-55r/min, and the rotating speed of the lower fixed soft abrasive grinding disc is 90-110 r/min;
the polishing pressure of the upper fixed soft abrasive grinding disc and the lower fixed soft abrasive grinding disc is 0.5-0.6 MPa;
The polishing time of the mechanical chemical polishing of the double-sided fixed soft abrasive grinding disc is 50-70min, and the cooling mode is continuous cooling by adopting deionized water.
9. the method of claim 1, wherein the soft abrasive is one or more combinations of SiO2, CeO2, Fe2O3, α -Al2O 3;
The binding agent is a magnesium oxychloride binding agent;
The manufacturing process of the upper fixed soft abrasive grinding disc and the lower fixed soft abrasive grinding disc is as follows:
screening MgO by using a sieve with the specification of 300#, and drying the MgO and a soft abrasive with the particle size of W1-W3 in a blast oven for 60min at the temperature of 40 ℃ to obtain a dry mixture; preparing a MgCl2 solution with the mass fraction of 70-80%, mixing with the dry mixture, ensuring that the molar ratio of MgO/MgCl2 is 5:1, stirring the mixture evenly, pouring the mixture into a mold, covering the mold with a pressing plate, and curing the mixture at normal temperature for more than 2 weeks; the fully cured abrasive block was bonded to the cast iron substrate of the upper and lower bonded soft abrasive discs with 504AB glue and the upper and lower bonded soft abrasive discs were dressed using electroplated diamond dressing rings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910754849.0A CN110539209B (en) | 2019-08-15 | 2019-08-15 | Processing method of thin plate-shaped sapphire wafer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910754849.0A CN110539209B (en) | 2019-08-15 | 2019-08-15 | Processing method of thin plate-shaped sapphire wafer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110539209A true CN110539209A (en) | 2019-12-06 |
| CN110539209B CN110539209B (en) | 2021-05-25 |
Family
ID=68711631
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910754849.0A Active CN110539209B (en) | 2019-08-15 | 2019-08-15 | Processing method of thin plate-shaped sapphire wafer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110539209B (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112548883A (en) * | 2020-12-02 | 2021-03-26 | 西安奕斯伟硅片技术有限公司 | Grinding wheel and grinding equipment |
| CN112563132A (en) * | 2020-11-13 | 2021-03-26 | 北京遥测技术研究所 | Rapid thinning and polishing method for surface heterostructure |
| CN112658974A (en) * | 2020-12-17 | 2021-04-16 | 江苏集萃精凯高端装备技术有限公司 | YAG wafer grinding method |
| CN112792726A (en) * | 2021-01-04 | 2021-05-14 | 大连理工大学 | High-precision machining method for weak-rigidity flat plate |
| WO2022095456A1 (en) * | 2020-11-06 | 2022-05-12 | 华侨大学 | Method for grinding diamond substrate |
| CN116254094A (en) * | 2023-01-05 | 2023-06-13 | 燕山大学 | Diamond micro powder aggregate based on ceramic bond and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001198808A (en) * | 2000-01-24 | 2001-07-24 | Morioka Seiko Kogyo Kk | Double-sided mirror finished sapphire substrate and its manufacturing method |
| US6632127B1 (en) * | 2001-03-07 | 2003-10-14 | Jerry W. Zimmer | Fixed abrasive planarization pad conditioner incorporating chemical vapor deposited polycrystalline diamond and method for making same |
| CN101376228A (en) * | 2008-09-28 | 2009-03-04 | 大连理工大学 | Method for grinding soft crisp functional crystal |
| CN102172879A (en) * | 2011-02-23 | 2011-09-07 | 南京航空航天大学 | Method for processing soft and crisp LBO crystals based on consolidated abrasive polishing pad |
| CN104669105A (en) * | 2013-11-26 | 2015-06-03 | 浙江上城科技有限公司 | Two-surface grinding method of sapphire touch panel |
| CN205674012U (en) * | 2016-06-08 | 2016-11-09 | 江苏吉星新材料有限公司 | A kind of sapphire is thinning to be processed with two-sided solidified abrasive grinding mechanism |
| CN106425825A (en) * | 2016-09-28 | 2017-02-22 | 南京航空航天大学 | New grinding and polishing method for super hard and brittle workpiece |
-
2019
- 2019-08-15 CN CN201910754849.0A patent/CN110539209B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001198808A (en) * | 2000-01-24 | 2001-07-24 | Morioka Seiko Kogyo Kk | Double-sided mirror finished sapphire substrate and its manufacturing method |
| US6632127B1 (en) * | 2001-03-07 | 2003-10-14 | Jerry W. Zimmer | Fixed abrasive planarization pad conditioner incorporating chemical vapor deposited polycrystalline diamond and method for making same |
| CN101376228A (en) * | 2008-09-28 | 2009-03-04 | 大连理工大学 | Method for grinding soft crisp functional crystal |
| CN102172879A (en) * | 2011-02-23 | 2011-09-07 | 南京航空航天大学 | Method for processing soft and crisp LBO crystals based on consolidated abrasive polishing pad |
| CN104669105A (en) * | 2013-11-26 | 2015-06-03 | 浙江上城科技有限公司 | Two-surface grinding method of sapphire touch panel |
| CN205674012U (en) * | 2016-06-08 | 2016-11-09 | 江苏吉星新材料有限公司 | A kind of sapphire is thinning to be processed with two-sided solidified abrasive grinding mechanism |
| CN106425825A (en) * | 2016-09-28 | 2017-02-22 | 南京航空航天大学 | New grinding and polishing method for super hard and brittle workpiece |
Non-Patent Citations (3)
| Title |
|---|
| 张瑜: "蓝宝石高效低损伤加工工艺研究", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 * |
| 王晨宇: "单晶蓝宝石基片双面研磨工艺研究", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 * |
| 臧江龙: "单晶蓝宝石基片固结磨料机械化学抛光技术", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022095456A1 (en) * | 2020-11-06 | 2022-05-12 | 华侨大学 | Method for grinding diamond substrate |
| CN112563132A (en) * | 2020-11-13 | 2021-03-26 | 北京遥测技术研究所 | Rapid thinning and polishing method for surface heterostructure |
| CN112548883A (en) * | 2020-12-02 | 2021-03-26 | 西安奕斯伟硅片技术有限公司 | Grinding wheel and grinding equipment |
| CN112658974A (en) * | 2020-12-17 | 2021-04-16 | 江苏集萃精凯高端装备技术有限公司 | YAG wafer grinding method |
| CN112792726A (en) * | 2021-01-04 | 2021-05-14 | 大连理工大学 | High-precision machining method for weak-rigidity flat plate |
| CN116254094A (en) * | 2023-01-05 | 2023-06-13 | 燕山大学 | Diamond micro powder aggregate based on ceramic bond and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110539209B (en) | 2021-05-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110539209B (en) | Processing method of thin plate-shaped sapphire wafer | |
| CN101870091B (en) | Method for preparing ultra-fine diamond grinding wheel of vitrified bond | |
| CN104999365A (en) | Sapphire wafer grinding and polishing method | |
| CN108188948B (en) | Multi-layer abrasive particle abrasive belt structure and manufacturing method thereof | |
| CN111216037B (en) | Polishing pad and preparation method thereof | |
| Chen et al. | Relationship between mechanical properties and processing performance of agglomerated diamond abrasive compared with single diamond abrasive | |
| CN100500375C (en) | Semi-sessile abrasive grain polishing method of plane stainless steel | |
| CN105856089A (en) | Grinding composite body and preparation method thereof | |
| CN108453619B (en) | Thinning grinding wheel for sapphire substrate | |
| CN110890271A (en) | Processing method of silicon carbide wafer | |
| CN102513919A (en) | Method for grinding aluminum oxide ceramic ball based on soft grinding material fixation grinding tool | |
| CN104669129A (en) | Ceramics titanizing CBN (cubic boron nitride) grinding wheel and preparation method thereof | |
| JP2011077413A (en) | Method for manufacturing silicon wafer | |
| CN103273432B (en) | Formulation of zirconium oxide and aluminum oxide ceramic mirror polishing pellet tablet fixation grinding material | |
| CN111347354B (en) | Grinding wheel for thinning silicon carbide crystal, preparation method and application thereof | |
| CN111100599A (en) | Superhard aggregate abrasive with high micro-crushing characteristic and preparation method thereof | |
| CN203426874U (en) | Resin binder and ceramic binder composite cubic boron nitride plane grinding wheel | |
| Deng et al. | Preparation and processing properties of magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction lapping-polishing plate for single-crystal 4H-SiC | |
| CN105690240B (en) | A kind of flexible polishing pad | |
| CN102407483A (en) | High-efficiency nano-precision reducing method for semiconductor wafer | |
| WO2015050218A1 (en) | Method for producing polished article | |
| CN104772693A (en) | Diamond grinding pad for processing super-hard ceramics and preparation method for diamond grinding pad | |
| CN110757329A (en) | Metal surface polishing treatment process | |
| CN108098569B (en) | Neodymium-contained soft abrasive fixing grinding tool for polishing sapphire wafer and manufacturing method thereof | |
| CN102528641A (en) | Ceramic ball lapping method based on combined-type fixation abrasive material grinding disc |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |