Gradient structure composite grinding wheel with self-repairing function and manufacturing method thereof

Abstract

The application discloses a gradient structure composite grinding wheel with a self-repairing function and a manufacturing method thereof. The grinding wheel is composed of a base layer, a transition layer and a repairing layer. The base layer is a porous metal ceramic substrate. The transition layer is a binder powder and is arranged between the porous metal ceramic substrate and a functional layer. The functional layer has a working surface on the outer side. Spiral micro-grooves are arranged on the working surface. Self-repairing units are encapsulated in the micro-grooves. The application adopts a multilayer composite gradient structure design. The functional layer is divided into a bottom layer, an intermediate layer and a surface layer. The bottom layer bears the main grinding amount. The intermediate layer realizes fine machining. The surface layer reduces the friction coefficient, enhances the pore structure, enhances heat dissipation, reduces thermal stress and effectively improves the comprehensive performance and service life of the grinding wheel.

Description

Technical Field

[0001] The invention belongs to the technical field of wafer chamfering grinding wheel manufacturing, and particularly relates to a gradient structure composite grinding wheel with a self-repairing function and a manufacturing method thereof. Background Art

[0002] A wafer chamfering wheel is a grinding tool specifically designed for chamfering the edges of semiconductor wafers. Its primary function is to remove burrs, cracks, and irregularities from the wafer edge, improving edge quality and ultimately enhancing the yield of subsequent processes and device performance. Wafer chamfering wheels must simultaneously meet the requirements of high precision, high wear resistance, and minimal damage. Existing chamfering wheels typically use a single material (such as a single resin or metal bond). These products suffer from the following issues: Resin bonds have poor heat resistance and easily soften at high temperatures, resulting in a short wheel life; metal bonds (such as copper and iron-based) are hard but lack toughness, easily causing microcracks on the wafer edge during processing. Furthermore, existing wafer chamfering wheels lack self-healing capabilities, and their cutting performance cannot be restored after wear.

[0003] To this end, a gradient structure composite grinding wheel with self-repairing function and a manufacturing method thereof are designed to overcome the above problems. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a gradient structure composite grinding wheel with self-repairing function and a manufacturing method thereof, which has a simple and reasonable structure, a simple and reliable preparation process, reduces thermal stress, and effectively improves the comprehensive performance and service life of the grinding wheel.

[0005] The present invention is achieved through the following technical solution: a gradient structure composite grinding wheel with self-repairing function, the grinding wheel consisting of a base layer, a transition layer, and a functional layer, the base layer is a porous metal ceramic substrate, a transition layer is arranged on the porous metal ceramic substrate, the transition layer is a binder powder, arranged on the porous metal ceramic substrate and between the functional layer, and formed to a certain thickness, the outward side of the functional layer is a working surface, a spiral micro groove is arranged on the working surface, and a self-repairing unit is encapsulated in the micro groove.

[0006] Preferably, the porous metal ceramic substrate is made of WC-Co powder and nano-Al2O3, wherein the ratio of WC-Co powder to nano-Al2O3 is 7:3.

[0007] Preferably, the binder powder is made by grinding diamond, CBN and NiCrAlY, and the thickness of the transition layer made of the binder powder is 200 μm.

[0008] Preferably, the functional layer is a gradient-distributed sandwich functional layer, which consists of a bottom layer, a middle layer, and an outer layer, wherein the bottom layer is composed of diamond micropowder and Cu-Sn-Ti alloy powder, the middle layer is a nanodiamond-ceramic composite, and the outer layer is a diamond carbon surface layer.

[0009] Preferably, the self-repairing unit is made of low-melting-point Sn-Bi alloy microspheres and nano-diamond sustained-release capsules, the mixture is filled into the groove by electrostatic spraying, and is encapsulated by a SiO2 sol-gel protective film.

[0010] A method for manufacturing a gradient structure composite grinding wheel with self-repairing function, the method comprising the following steps:

[0011] Step 1: preparing a porous metal ceramic matrix layer;

[0012] Step 2: depositing a diamond / CBN mixed abrasive transition layer on the substrate layer;

[0013] Step 3: constructing a gradient-distributed sandwich functional layer on the transition layer;

[0014] Step 4: Opening spiral micro-grooves on the working surface of the functional layer and encapsulating the self-repairing unit;

[0015] Step 5: Determine whether the grinding wheel meets the use requirements. If not, return to step 1 and re-prepare. If yes, proceed to step 6.

[0016] Step 6: Perform subsequent processing or use on the grinding wheel.

[0017] As a preference: the specific method for making the base layer in step 1 is:

[0018] Step 101: ball-milling WC-Co powder and nano-Al2O3 in a ratio of 7:3;

[0019] Step 102: molding the mixed powder;

[0020] Step 103: vacuum sintering the molded body to obtain a porous metal ceramic substrate.

[0021] As a preferred method, the specific method for making the transition layer in step 2 is:

[0022] Step 201: preparing diamond, CBN and NiCrAlY binder powders;

[0023] Step 202: Depositing powder on the surface of the substrate layer using a plasma spraying process;

[0024] Step 203: forming a transition layer with a thickness of 200 μm.

[0025] As a preferred method, the specific method for making the sandwich functional layer in step 3 is:

[0026] Step 301: hot-pressing and sintering diamond powder and Cu-Sn-Ti alloy powder to prepare a bottom layer;

[0027] Step 302: depositing a nano-diamond-ceramic composite intermediate layer on the bottom layer using a chemical vapor infiltration process;

[0028] Step 303: A diamond-like carbon surface layer is coated on the intermediate layer using a magnetron sputtering process.

[0029] As a preferred method, the specific method of forming the spiral micro-grooves and encapsulating the self-repairing units in step 4 is:

[0030] Step 401: using laser micromachining to create spiral microgrooves on the working surface of the functional layer;

[0031] Step 402: Fill the groove with a mixture of low-melting-point alloy microspheres and nano-diamond sustained-release capsules;

[0032] Step 403: Cover with a SiO2 sol-gel protective film to encapsulate the self-repairing unit.

[0033] The beneficial effects of the present invention are as follows:

[0034] 1) It adopts a multi-layer composite gradient structure design. The functional layer is divided into a bottom layer, a middle layer and a surface layer. The bottom layer bears the main grinding amount, the middle layer realizes fine processing, and the surface layer reduces the friction coefficient. The pore structure enhances heat dissipation and reduces thermal stress, effectively improving the comprehensive performance of the grinding wheel.

[0035] 2) Spiral micro-grooves are created on the working surface of the grinding wheel, pre-embedded with low-melting-point alloy microspheres and nano-diamond sustained-release capsules. This enables in-situ repair of worn areas and continuous release of nano-abrasives to maintain cutting edge sharpness, effectively extending the service life of the grinding wheel.

[0036] 3) The preparation process adopts mature processes such as plasma spraying, hot pressing sintering, and chemical vapor infiltration, and the preparation process is simple and reliable.

[0037] The grinding wheel of this invention utilizes a porous metal-ceramic matrix, a transition layer composed of a diamond / CBN mixed abrasive, and a gradient-distributed functional layer sandwich structure, comprising a base layer of micronized diamonds, a middle layer of nanodiamonds, and a surface layer of diamond-like carbon coating. Furthermore, spiral microgrooves are embedded in the working surface of the grinding wheel, containing low-melting-point alloy microspheres and nanodiamond sustained-release capsules. This allows for in-situ repair of worn areas and continuous release of nanoabrasives. This design effectively improves the wear resistance, heat dissipation, and service life of the grinding wheel.

[0038] The composite grinding wheel preparation method of the present invention includes steps such as base layer preparation, transition layer deposition, functional layer construction, and self-repair unit packaging. The entire preparation process is simple and highly reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to more clearly understand the objectives, technical solutions and advantages of the present invention, the present invention is further described below with reference to the accompanying drawings and embodiments.

[0041] In the description of the present invention, it should be understood that the orientations or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “inside”, “outside”, “horizontal” and “vertical” are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or component referred to must have a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] The present invention will be described in detail below with reference to the accompanying drawings: Figure 1 As shown, a gradient structure composite grinding wheel with self-repairing function is provided. The grinding wheel consists of a base layer, a transition layer, and a functional layer. The base layer is a porous metal ceramic substrate. A transition layer is provided on the porous metal ceramic substrate. The transition layer is a binder powder and is provided between the porous metal ceramic substrate and the functional layer to form a certain thickness. The outward side of the functional layer is a working surface, on which spiral micro-grooves are provided, and a self-repairing unit is encapsulated in the micro-grooves.

[0043] Preferably, the porous metal ceramic substrate is made of WC-Co powder and nano-Al2O3, with the ratio of WC-Co powder to nano-Al2O3 being 7:3. The binder powder is made by grinding diamond, CBN, and NiCrAlY, and the thickness of the transition layer made from this binder powder is 200μm. The functional layer is a gradient sandwich functional layer consisting of a base layer, a middle layer, and an outer layer. The base layer is composed of diamond micropowder and Cu-Sn-Ti alloy powder, the middle layer is a nano-diamond-ceramic composite, and the outer layer is a diamond carbon surface layer.

[0044] The self-repairing unit is made of low-melting-point Sn-Bi alloy microspheres and nano-diamond sustained-release capsules. The mixture is filled into the groove by electrostatic spraying and encapsulated by a SiO2 sol-gel protective film.

[0045] A method for manufacturing a gradient structure composite grinding wheel with self-repairing function, the method comprising the following steps:

[0046] Step 1: preparing a porous metal ceramic matrix layer;

[0047] Step 2: depositing a diamond / CBN mixed abrasive transition layer on the substrate layer;

[0048] Step 3: constructing a gradient-distributed sandwich functional layer on the transition layer;

[0049] Step 4: Opening spiral micro-grooves on the working surface of the functional layer and encapsulating the self-repairing unit;

[0050] Step 5: Determine whether the grinding wheel meets the use requirements. If not, return to step 1 and re-prepare. If yes, proceed to step 6.

[0051] Step 6: Perform subsequent processing or use on the grinding wheel.

[0052] The specific method for making the base layer in step 1 is:

[0053] Step 101: ball-milling WC-Co powder and nano-Al2O3 in a ratio of 7:3;

[0054] Step 102: molding the mixed powder;

[0055] Step 103: vacuum sintering the molded body to obtain a porous metal ceramic substrate.

[0056] The specific method for making the transition layer in step 2 is:

[0057] Step 201: preparing diamond, CBN and NiCrAlY binder powders;

[0058] Step 202: Depositing powder on the surface of the substrate layer using a plasma spraying process;

[0059] Step 203: forming a transition layer with a thickness of 200 μm.

[0060] The specific method for making the sandwich functional layer in step 3 is:

[0061] Step 301: hot-pressing and sintering diamond powder and Cu-Sn-Ti alloy powder to prepare a bottom layer;

[0062] Step 302: depositing a nano-diamond-ceramic composite intermediate layer on the bottom layer using a chemical vapor infiltration process;

[0063] Step 303: A diamond-like carbon surface layer is coated on the intermediate layer using a magnetron sputtering process.

[0064] As a preferred method, the specific method of forming the spiral micro-grooves and encapsulating the self-repairing units in step 4 is:

[0065] Step 401: using laser micromachining to create spiral microgrooves on the working surface of the functional layer;

[0066] Step 402: Fill the groove with a mixture of low-melting-point alloy microspheres and nano-diamond sustained-release capsules;

[0067] Step 403: Cover with a SiO2 sol-gel protective film to encapsulate the self-repairing unit.

[0068] The grinding wheel of this invention utilizes a porous metal-ceramic matrix, a transition layer composed of a diamond / CBN mixed abrasive, and a gradient-distributed functional layer sandwich structure, comprising a base layer of micronized diamonds, a middle layer of nanodiamonds, and a surface layer of diamond-like carbon coating. Furthermore, spiral microgrooves are embedded in the working surface of the grinding wheel, containing low-melting-point alloy microspheres and nanodiamond sustained-release capsules. This allows for in-situ repair of worn areas and continuous release of nanoabrasives. This design effectively improves the wear resistance, heat dissipation, and service life of the grinding wheel.

[0069] The composite grinding wheel preparation method of the present invention includes steps such as base layer preparation, transition layer deposition, functional layer construction, and self-repair unit packaging. The entire preparation process is simple and highly reliable.

[0070] Example 1:

[0071] A method for preparing a gradient structure composite grinding wheel with self-repairing function comprises the following steps:

[0072] Step 1: Prepare a porous metal ceramic matrix layer:

[0073] Step 101: WC-Co powder (particle size 1-3 μm) and nano-Al2O3 (particle size 50 nm) were ball-milled at a mass ratio of 7:3 (argon protection, speed 300 rpm × 8 hours). The nano-Al2O3 (50 nm) was surface activated, ultrasonically cleaned (ethanol medium, 40 kHz × 30 minutes), and modified with an alkane coupling agent (KH550, concentration 2 wt%).

[0074] Step 102: Press the mixed powder into a mold at a pressure of 50 MPa and maintain the pressure for 10 minutes;

[0075] Step 103 , vacuum sintering the molded body at a temperature of 1450° C., a holding time of 2 hours, a heating rate of 5° C. / min, and argon protection to obtain a porous metal ceramic substrate with a porosity of 15%.

[0076] Step 2: Depositing a diamond / CBN mixed abrasive transition layer on the substrate layer:

[0077] Step 201: Prepare powder, including 60% diamond powder (particle size 5 μm), 40% CBN powder (particle size 3 μm), and NiCrAlY binder;

[0078] Step 202: Deposit powder on the surface of the substrate layer using a plasma spraying process with a power of 45 kW and a powder feeding rate of 30 g / min.

[0079] Step 203 : Real-time monitoring by a laser thickness gauge to form a transition layer with a thickness of 200 μm and an interface bonding strength of ≥300 MPa.

[0080] Step 3: Construct a gradient-distributed sandwich functional layer on the transition layer:

[0081] Step 301: hot pressing and sintering to prepare the bottom layer at a temperature of 800°C, a pressure of 50 MPa, and a holding time of 1 hour. The raw materials are diamond powder (800#, accounting for 60%) and Cu-Sn-Ti alloy powder (accounting for 40%).

[0082] Step 302: Depositing a nanodiamond-ceramic composite intermediate layer on the bottom layer using a chemical vapor infiltration process at a temperature of 750° C., a methane / hydrogen volume ratio of 1:10, and a deposition time of 6 hours to obtain a nanodiamond (2000#, accounting for 30%)-Al2O3 ceramic composite layer;

[0083] Step 303: A diamond-like carbon surface layer is deposited on the intermediate layer using a magnetron sputtering process. The target material is high-purity graphite (purity 99.999%), the argon flow rate is 50 sccm, the bias voltage is -150 V, the coating thickness is 2 μm, the sp³ bond content is greater than 70%, and the hardness is 35 GPa.

[0084] Step 4: Create spiral micro-grooves on the working surface of the functional layer and encapsulate the self-repairing unit:

[0085] Step 401: Use fiber laser micromachining (wavelength 1064nm, power 20W) to create spiral micro grooves on the working surface of the functional layer, with a groove width of 50μm, a depth of 150μm, and a pitch of 0.3mm;

[0086] Step 402: low-melting-point Sn-Bi alloy microspheres (melting point 138° C.) and nanodiamond sustained-release capsules (shell material: polyimide, core material: 3 nm diamond particles) are mixed in a mass ratio of 1:1, and the mixture is filled into the groove by electrostatic spraying;

[0087] Step 403: Cover with a SiO2 sol-gel protective film (thickness 10 μm) to encapsulate the self-repairing unit.

[0088] Step 5: Determine whether the grinding wheel meets the use requirements. If not, return to step 1 and re-prepare. If yes, proceed to step 6.

[0089] Step 6: Perform subsequent processing or use on the grinding wheel.

[0090] Example 2:

[0091] A method for preparing a gradient structure composite grinding wheel with self-repairing function comprises the following steps:

[0092] Step 1: Prepare a porous metal ceramic matrix layer:

[0093] Step 101: WC-Co powder (particle size 1-3 μm) and nano-Al2O3 (particle size 50 nm) were ball-milled at a mass ratio of 7:3 (argon protection, speed 300 rpm × 4 hours). The nano-Al2O3 (50 nm) was surface activated, ultrasonically cleaned (ethanol medium, 40 kHz × 30 minutes), and modified with an alkane coupling agent (KH550, concentration 2 wt%).

[0094] Step 102: Press the mixed powder into a mold at a pressure of 200 MPa and maintain the pressure for 10 minutes;

[0095] Step 103 , vacuum sintering the molded body at a temperature of 1500° C., a holding time of 2.5 hours, a heating rate of 10° C. / min, and argon protection to obtain a porous metal ceramic substrate with a porosity of 18%.

[0096] Step 2: Depositing a diamond / CBN mixed abrasive transition layer on the substrate layer:

[0097] Step 201: Prepare powder, including 55% diamond powder (particle size 8 μm), 45% CBN powder (particle size 5 μm), and NiCrAlY binder;

[0098] Step 202: Deposit powder on the surface of the substrate layer using a plasma spraying process with a power of 50 kW and a powder feeding rate of 35 g / min;

[0099] Step 203 : Real-time monitoring by a laser thickness gauge to form a transition layer with a thickness of 180 μm and an interface bonding strength of ≥320 MPa.

[0100] Step 3: Construct a gradient-distributed sandwich functional layer on the transition layer:

[0101] Step 301: Prepare the bottom layer by hot pressing and sintering at a temperature of 850°C, a pressure of 60 MPa, and a holding time of 1.2 hours. The raw materials are diamond powder (700#, accounting for 65%) and Cu-Sn-Ti alloy powder (accounting for 35%).

[0102] Step 302: Depositing a nano-diamond-ceramic composite intermediate layer on the bottom layer using a chemical vapor infiltration process at a temperature of 780° C., a methane / hydrogen volume ratio of 1:9, and a deposition time of 7 hours to obtain a nano-diamond (1800#, accounting for 25%)-Al2O3 ceramic composite layer;

[0103] Step 303: A diamond-like carbon surface layer is deposited on the intermediate layer using a magnetron sputtering process. The target material is high-purity graphite (purity 99.999%), the argon flow rate is 45 sccm, the bias voltage is -120 V, the coating thickness is 1.8 μm, the sp³ bond content is greater than 75%, and the hardness is 38 GPa.

[0104] Step 4: Create spiral micro-grooves on the working surface of the functional layer and encapsulate the self-repairing unit:

[0105] Step 401: Use fiber laser micromachining (wavelength 1064nm, power 25W) to create spiral micro grooves on the working surface of the functional layer, with a groove width of 60μm, a depth of 180μm, and a pitch of 0.25mm;

[0106] Step 402: low-melting-point Sn-Bi-In alloy microspheres (melting point 125° C.) and nanodiamond sustained-release capsules (shell material: polyimide, core material: 5 nm diamond particles) are mixed at a mass ratio of 1.2:1, and the mixture is filled into the groove by electrostatic spraying;

[0107] Step 403: Cover with a SiO2 sol-gel protective film (8 μm thick) to encapsulate the self-repairing unit.

[0108] Step 5: Determine whether the grinding wheel meets the use requirements. If not, return to step 1 and re-prepare. If yes, proceed to step 6.

[0109] Step 6: Perform subsequent processing or use on the grinding wheel.

[0110] The specific embodiments described herein are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical concepts disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A gradient structure composite grinding wheel with self-repairing function, characterized by: The grinding wheel consists of a base layer, a transition layer, and a functional layer. The base layer is a porous metal ceramic substrate, on which a transition layer is arranged. The transition layer is a binder powder, which is arranged between the porous metal ceramic substrate and the functional layer and has a certain thickness. The outward side of the functional layer is a working surface, on which spiral microgrooves are arranged, and a self-repairing unit is encapsulated in the microgrooves. The functional layer is a gradient-distributed sandwich functional layer, which consists of a bottom layer, an intermediate layer, and an outer layer. The bottom layer is composed of diamond micropowder and Cu-Sn-Ti alloy powder, the intermediate layer is a nanodiamond-ceramic composite, and the outer layer is a diamond carbon surface layer. The self-repairing unit is made of low-melting-point Sn-Bi alloy microspheres and nanodiamond sustained-release capsules. The mixture is filled into the groove by electrostatic spraying and encapsulated by a SiO2 sol-gel protective film.

2. The gradient structure composite grinding wheel with self-repairing function according to claim 1, characterized in that: The porous metal ceramic substrate is made of WC-Co powder and nano-Al2O3, wherein the ratio of WC-Co powder to nano-Al2O3 is 7:

3.

3. The gradient structure composite grinding wheel with self-repairing function according to claim 1, characterized in that: The binder powder is made by grinding diamond, CBN and NiCrAlY, and the thickness of the transition layer made of the binder powder is 200 μm.

4. The method for manufacturing a self-repairing gradient structure composite grinding wheel according to claim 1, characterized in that: The method comprises the following steps: Step 1: preparing a porous metal ceramic matrix layer; Step 2: depositing a diamond / CBN mixed abrasive transition layer on the substrate layer; Step 3: constructing a gradient-distributed sandwich functional layer on the transition layer; Step 4: Opening spiral micro-grooves on the working surface of the functional layer and encapsulating the self-repairing unit; Step 5: Determine whether the grinding wheel meets the use requirements. If yes, return to step 1 to prepare it again. If not, go to step 6. Step 6: Perform subsequent processing or use on the grinding wheel.

5. The method for manufacturing a self-repairing gradient structure composite grinding wheel according to claim 4, characterized in that: The specific method for making the base layer in step 1 is: Step 101: ball-milling WC-Co powder and nano-Al2O3 in a ratio of 7:3; Step 102: molding the mixed powder; Step 103: vacuum sintering the molded body to obtain a porous metal ceramic substrate.

6. The method for manufacturing a self-repairing gradient structure composite grinding wheel according to claim 4, characterized in that: The specific method for making the transition layer in step 2 is: Step 201: preparing diamond, CBN and NiCrAlY binder powders; Step 202: Depositing powder on the surface of the substrate layer using a plasma spraying process; Step 203: forming a transition layer with a thickness of 200 μm.

7. The method for manufacturing a self-repairing gradient structure composite grinding wheel according to claim 4, characterized in that: The specific method for making the sandwich functional layer in step 3 is: Step 301: hot-pressing and sintering diamond powder and Cu-Sn-Ti alloy powder to prepare a bottom layer; Step 302: depositing a nano-diamond-ceramic composite intermediate layer on the bottom layer using a chemical vapor infiltration process; Step 303: A diamond-like carbon surface layer is coated on the intermediate layer using a magnetron sputtering process.

8. The method for manufacturing a self-repairing gradient structure composite grinding wheel according to claim 4, characterized in that: The specific method of forming the spiral micro-grooves and encapsulating the self-repairing units in step 4 is as follows: Step 401: using laser micromachining to create spiral microgrooves on the working surface of the functional layer; Step 402: Fill the groove with a mixture of low-melting-point alloy microspheres and nano-diamond sustained-release capsules; Step 403: Cover with a SiO2 sol-gel protective film to encapsulate the self-repairing unit.

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