A silicon carbide multi-functional high-speed rotary grinding machine

Abstract

A multi-functional high-speed rotary grinding machine, comprising a bed component, a grinding wheel headstock component, a tailstock component, a crystal orientation detection mechanism, a headstock component, and a dimension detection mechanism mounted on the bed component. The bed component includes a bed, a worktable, a workpiece support, a rotating shaft, and a rack. A plurality of feet are provided at the bottom of the bed, and the installation surface of the bed is ensured to be horizontal by adjusting the height of the feet. The upper surface of the worktable is used for installing the headstock component and the tail component, and a plurality of mounting holes for the tailstock component are drilled on its surface, and the requirement of machining workpieces with different lengths can be met by moving the tailstock component. The workpiece support is installed on the worktable and is used for holding the workpiece to be machined. In the present invention, by simplifying the workpiece clamping, multiple grinding heads are adopted and formed grinding wheels are installed to realize multi-functional grinding with one machine; high-speed machining is adopted, the cutting linear speed of the main grinding head grinding wheel reaches 60-80 m / s, and at the same time, the headstock drives the workpiece to rotate at a speed of 300 rpm. Due to the high processing speed and the diversification of processing functions, the processing efficiency increases exponentially.

Description

Technical Field

[0001] The present invention relates to a grinding machine, and more particularly to a multi-functional high-speed circular grinding machine for silicon carbide. Background Art

[0002] The high-frequency device wafers made of silicon carbide material have excellent characteristics such as a bandgap, drift velocity, breakdown voltage, thermal conductivity, and high temperature resistance that are several times higher than those of traditional silicon. The present invention relates to the equipment required for the application of the circular rolling process of the ingot in the production process of silicon carbide wafers.

[0003] The domestic development of silicon carbide wafer processing started relatively late and heavily relied on imports. Most of the processing equipment was imported equipment. In recent years, the domestic wafer industry has developed rapidly, but there are very few domestic processing equipment manufacturers, and most of them also use the traditional external cylindrical grinding method to grind the outer circle of the ingot, and the grinding head design lacks processing versatility.

[0004] The main disadvantages of using a traditional external cylindrical grinding machine to grind silicon carbide ingots are as follows:

[0005] 1. Low processing efficiency, and the single-piece processing time exceeds 6 hours. The high hardness of silicon carbide is second only to diamond, and it is difficult to achieve grinding with a high-rigidity and high-speed grinding head on traditional external cylindrical grinding equipment.

[0006] 2. Lack of processing versatility. The processing function is single, and the external cylindrical grinding wheel can only grind the outer circle and cannot simultaneously meet the requirement of grinding the end face (crystal reference plane) on the outer circle required in wafer processing. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a double-screw spindle synchronous feed drive system for a double-sided grinding machine that can improve the overall rigidity and feed accuracy of the spindle assembly.

[0008] The technical solution adopted by the present invention to solve its technical problems is a multi-functional high-speed circular grinding machine, which includes a bed body component and a grinding wheel frame component, a tailstock component, a crystal orientation detection mechanism, a headstock component, and a dimension detection mechanism installed on the bed body component. The bed body component includes a bed body, a workbench, a workpiece bracket, a rotating shaft, and a rack. A plurality of feet are provided at the bottom of the bed body, and the installation surface of the bed body is ensured to be horizontal by adjusting the height of the feet. The upper surface of the workbench is used to install the headstock component and the tailstock component, and a plurality of installation holes for the tailstock component are drilled on its surface, and the requirement of processing workpieces with different lengths can be met by moving the tailstock component. The workpiece bracket is installed on the workbench and is used to hold the workpiece to be processed.

[0009] Furthermore, the bed body component is also provided with a rotating shaft and a rack. The rotating shaft 14 is used to adjust the axial taper of the workpiece to ensure the consistency of the diameter size, and the rack is a part of the transverse moving gear rack of the crystal orientation detection mechanism.

[0010] Furthermore, the grinding wheel headstock assembly includes a main grinding head front-back feed mechanism, a main grinding head, a main grinding head up-down feed mechanism, a sub-grinding head, a sub-grinding head front-back feed mechanism, and a left-right feed mechanism for the two grinding heads of the grinding wheel headstock. The main grinding head and the sub-grinding head are respectively mounted on pallets allowing front-back / left-right feeding. The main grinding head front-back feed mechanism is used to ensure the feed rate of the workpiece being machined. The main grinding head allows movement in three directions: left-right, up-down, and front-back. The main grinding head up-down feed mechanism switches the working state to grind the outer circle or the end face. The sub-grinding head feed mechanism is used to ensure the groove depth and positional tolerance requirements. The left-right feed mechanism for the two grinding heads of the grinding wheel headstock ensures the accuracy requirements within the grinding stroke range.

[0011] Furthermore, the tailstock assembly includes a tailstock workpiece ejector rod, a telescoping mechanism, a tailstock housing, a bushing, a clamping cylinder, and a tailstock movement mechanism. The tailstock workpiece ejector rod cooperates with the headstock end ejector rod to clamp the workpiece for grinding. A clearance is provided between the bushing and the telescoping mechanism to enable smooth telescoping of the mechanism without jamming. At the same time, the replaceable bushing can protect the housing. The clamping cylinder provides adjustable clamping force required for workpiece grinding. The tailstock movement mechanism is used to meet the position changes required within the workpiece machining length range.

[0012] Furthermore, the crystal orientation detection mechanism 4 includes a crystal orientation detection locator, a longitudinal feed mechanism, a mounting base, and a transverse feed mechanism. The crystal orientation detection locator determines the angle of the crystal line of the silicon carbide ingot through laser line detection and rotates the workpiece to the required machining position for grinding through an angle encoder; the arrival and departure of the crystal orientation detection locator at the measurement point are completed by the longitudinal feed mechanism and the transverse feed mechanism. Both move under servo control. The longitudinal movement is driven by a ball screw, and the transverse movement is driven by a rack and pinion.

[0013] Furthermore, the headstock assembly includes a headstock workpiece ejector rod, a headstock housing, a headstock rotating power shaft, a torque motor, and an angle rotation encoder. Angular contact bearings are installed at the front and back of the headstock rotating power shaft, a torque motor is installed in the middle, and an angle rotation encoder is installed at the tail. The torque motor rotates the headstock rotating power shaft to drive the workpiece to rotate for grinding. The angle rotation encoder can determine the rotation position of the torque motor at any time.

[0014] Furthermore, the dimension detection mechanism includes a laser measuring head, a mounting base, a telescoping and moving feed mechanism, and a cylinder. The dimension detection mechanism is installed on the headstock assembly. The laser measuring head measures the diameter and depth based on the displacement change by irradiating the workpiece surface with laser. The arrival and departure of the dimension measuring laser measuring head at the measurement point are achieved by the cylinder pushing the bracket to move along the linear guide pair. The laser measuring head detects the dimension data of the machined part at each machining stage. The mounting base is fixed on the headstock housing to limit the mounting measurement point.

[0015] The present invention simplifies the workpiece clamping, and realizes multi-functional grinding with one machine by using multiple grinding heads and installing profile grinding wheels; it adopts high-speed machining. The cutting linear speed of the grinding wheel of the main grinding head reaches 60 - 80 m / s, and at the same time, the headstock drives the workpiece to rotate at a speed of 300 rpm. Due to the high machining speed and the diversification of machining functions, the machining efficiency increases exponentially. Brief Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of an embodiment of the present invention;

[0017] Figure 2 is Figure 1 a schematic structural diagram of the bed body component in the shown embodiment;

[0018] Figure 3 is Figure 1 a schematic structural diagram of the grinding wheel headstock component in the shown embodiment;

[0019] Figure 4 is Figure 1 a schematic structural diagram of the tailstock component in the shown embodiment;

[0020] Figure 5 is Figure 1 a schematic structural diagram of the crystal orientation detection mechanism in the shown embodiment;

[0021] Figure 6 is Figure 1 a schematic structural diagram of the headstock component in the shown embodiment;

[0022] Figure 7 is Figure 1 a schematic structural diagram of the dimension detection mechanism in the shown embodiment.

[0023] In the figure: 1 - bed body component, 2 - grinding wheel headstock component, 3 - tailstock component, 4 - crystal orientation detection mechanism, 5 - headstock component, 6 - dimension detection mechanism 11 - bed body, 12 - workbench, 13 - workpiece support, 14 - rotating shaft, 15 - rack, 16 - foot pad 21 - main grinding head forward and backward feed mechanism, 22 - main grinding head, 23 - main grinding head up and down feed mechanism, 24 - sub - grinding head, 25 - sub - grinding head forward and backward feed mechanism, 26 - left and right feed mechanism for two grinding heads of the grinding wheel headstock 31 - tailstock workpiece ejector rod, 32 - telescopic mechanism, 33 - tailstock box body, 34 - bushing, 35 - clamping oil cylinder, 36 - tailstock moving mechanism 41 - crystal orientation detection and positioning instrument, 42 - longitudinal feed mechanism, 43 - installation base, 44 - transverse feed mechanism 51 - headstock workpiece ejector rod, 52 - headstock box body, 53 - headstock rotating power shaft, 54 - torque motor, 55 - angle rotation encoder, 61 - laser measurement head, 62 - installation base, 63 - telescopic and moving feed mechanism, 64 - air cylinder. Detailed Embodiment

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0025] Refer to the attached Figure 1-7 As shown, this embodiment includes a bed component 1, a grinding wheel headstock component 2, a tailstock component 3, a crystal orientation detection mechanism 4, a headstock component 5, and a dimension detection mechanism 6.

[0026] As Figure 2 shown, the bed component 1 mainly includes a bed 11, a workbench 12, a workpiece support 13, a rotating shaft 14, a rack 15, and a foot pad 16. Multiple foot pads 16 are provided at the bottom of the bed 11 to ensure the horizontal installation surface of the bed 11 by adjusting the height of the foot pads. The headstock component 5 and the tailstock component 3 are installed on the workbench 12, and multiple mounting holes for the tailstock component 3 are drilled on its surface. The requirement of processing workpieces with different lengths can be met by moving the tailstock component 3. The workpiece support 13 is installed on the workbench 12 to support the workpiece to be processed. The bed 11 adopts an integral box structure, and the material is 250 gray cast iron, which has compressive strength, wear resistance, and shock resistance. The workbench 2 and the bed 1 are connected as a whole during operation to ensure the rigidity requirement. The workpiece support 13 supports the installation of the workpiece to be processed and prevents the workpiece from falling. The rotating shaft 14 adjusts the axial taper of the workpiece to be processed to ensure the consistency of the diameter size. The rack 15 is part of the gear-rack for the lateral movement of the crystal orientation detection mechanism.

[0027] The processing method of this embodiment is carried out by fixing the workbench and moving the grinding wheel headstock. The bed 11 bears the workbench, and the headstock component 5 and the tailstock component 3 are fixedly installed on the workbench 12 of the machine tool component 1. The headstock component 5 and the tailstock component 3 clamp the workpiece against each other, and the main frame component 5 drives the work to rotate. At the same time, the grinding wheel headstock component 2 is controlled by a servo motor. The main grinding head installed therein is allowed to move up and down, forward and backward, and left and right, and the auxiliary grinding head is allowed to move forward and backward, and left and right. The forward and backward movement of the two grinding heads completes the cutting feed of the workpiece, and the left and right movement meets the cutting stroke requirement of the workpiece. The main grinding head can also move up and down to change the grinding part of the grinding wheel, cooperate with the working conditions of the workpiece movement, and grind the outer circle or the plane of the workpiece. During the processing, the crystal orientation detection mechanism 4 and the dimension detection mechanism 6 participate in the dimension control of the workpiece to be processed to achieve automatic grinding.

[0028] As Figure 3As shown in the figure, the grinding wheel headstock assembly 2 mainly includes the front and rear feed mechanism 21 of the main grinding head, the main grinding head 22, the up and down feed mechanism 23 of the main grinding head, the sub-grinding head 24, the front and rear feed mechanism 25 of the sub-grinding head, and the left and right feed mechanism 26 of the two grinding heads of the grinding wheel headstock. The main grinding head 22 and the sub-grinding head 24 are respectively installed on the pallets that allow front and rear / left and right feeding. The front and rear feed mechanism 21 of the main grinding head ensures the feed rate of the workpiece to be machined, and the minimum feed rate is 0.005. The grinding wheel of the main grinding head 22 uses an electroplated diamond formed grinding wheel, which is driven by an electric spindle with a rotational speed of 6000 - 10000 revolutions per minute. The main grinding head 22 is allowed to move in three directions: left and right, up and down, and front and rear. The movement is servo-controlled, advanced by a ball screw, and runs with high precision on a linear guide pair to grind the outer circle of the ingot and the reference surface (OFF surface) on the outer circle. The up and down feed mechanism 23 of the main grinding head switches the working state to grind the outer circle or the end face. The grinding wheel of the sub-grinding head 24 uses an electroplated diamond formed grinding wheel, and the grinding head is driven by a variable frequency motor through a multi-wedge belt with a grinding head rotational speed of 3000 revolutions per minute for high-speed grinding of the V-groove (NOTCH groove). The feed mechanism 25 of the sub-grinding head ensures the requirements for the groove depth and positional tolerance. The left and right feed mechanism 26 of the two grinding heads of the grinding wheel headstock ensures the accuracy requirements within the grinding stroke range.

[0029] As Figure 4 shown, the tailstock assembly 3 mainly includes: the tailstock workpiece ejector rod 31, the telescopic mechanism 32, the tailstock housing 33, the bushing 34, the clamping oil cylinder 35, and the tailstock movement mechanism 36. The tailstock workpiece ejector rod 31 cooperates with the ejector rod at the headstock end to clamp the workpiece for grinding. The telescopic mechanism 32 clamps the workpiece and leaves enough space for the installation of the workpiece. The material of the tailstock housing 33 is 250 gray cast iron, which is fixed on the workbench surface and has good rigidity and shock absorption. A clearance is provided between the bushing 34 and the telescopic mechanism to ensure smooth telescoping of the mechanism without jamming. At the same time, the replacement of the bushing can protect the housing. The clamping oil cylinder 35 provides adjustable clamping force required for workpiece grinding. The tailstock movement mechanism 36 meets the required position changes within the machining length range of the workpiece.

[0030] As Figure 5 shown, the crystal orientation detection mechanism 4 mainly includes: the crystal orientation detector 41, the longitudinal feed mechanism 42, the mounting base 43, and the transverse feed mechanism 44. The crystal orientation detector 41 determines the angle of the crystal line of the silicon carbide ingot through laser line detection and rotates the workpiece to the required machining position for grinding through an angle encoder; the arrival and departure of the crystal orientation detector 41 at the measurement point are completed by the longitudinal feed mechanism 42 and the transverse feed mechanism 44. The movement of both is servo-controlled, with the longitudinal movement driven by a ball screw and the transverse movement driven by a rack and pinion.

[0031] As Figure 6As shown in the figure, the headstock component mainly includes: the ejector rod 51 of the headstock machining part, the headstock housing 52, the headstock rotating power shaft 53, the torque motor 54, and the angle rotary encoder 55. Angular contact bearings are installed at the front and rear of the headstock rotating power shaft 53, the torque motor 54 is installed in the middle, with a rated speed of 300 rpm, and the angle rotary encoder 55 is installed at the tail. The torque motor 54 rotates the headstock rotating power shaft 53 to drive the workpiece to rotate for grinding. When grinding the OFF reference surface, the angle rotary encoder 55 stops the motor position according to the angle aligned by the detection crystal orientation instrument 41 for surface grinding. The ejector rod 51 of the headstock machining part cooperates with the ejector rod at the tailstock end to clamp the workpiece tightly for grinding. The headstock housing 52 is made of 250 gray cast iron and is fixed on the workbench surface, having good rigidity and shock absorption. The headstock rotating power shaft 53 uses large-angle angular contact bearings and long-span supports, with a headstock speed of 300 revolutions per minute, outputting strong power. The torque motor 54 is the power source of the headstock. The angle rotary encoder 55 judges the rotation position of the torque motor at any time.

[0032] As Figure 7 shown, the dimension detection mechanism 6 mainly includes: a laser measuring head 61, a mounting base 62, a telescopic moving feed mechanism 63, and a cylinder 64. The dimension detection mechanism 6 is installed on the headstock component 5. The laser measuring head 61 measures the diameter and depth according to the displacement change by irradiating the surface of the workpiece with laser. The position of the measuring head is adjustable to meet the measurement requirements of 4 - 8 inches. The laser measuring head 61 for dimension measurement reaches and leaves the measurement point by the cylinder 64 pushing the bracket to move along the linear guide pair. The laser measuring head 61 detects the dimension data of the machining part at each machining stage. The mounting base 62 is fixed on the headstock housing to install the measurement point limit. The telescopic moving feed mechanism 63 uses a linear guide pair to ensure the running accuracy. The cylinder 64 has multi-point limit for the stroke, and the air pressure is 0.4 - 0.6 Mpa.

[0033] On the one hand, the present invention simplifies the workpiece clamping, adopts multiple grinding heads and installs formed grinding wheels to realize multi-functional grinding with one machine. On the other hand, it adopts high-speed machining. The cutting linear speed of the main grinding head grinding wheel reaches 60 - 80 m / s, and at the same time, the headstock drives the workpiece to rotate at a speed of 300 rpm. Due to the improvement of high machining speed and multi-functionality, the machining efficiency has increased several times.

[0034] Among them, the advantages of this embodiment are mainly as follows:

[0035] (1) The main grinding wheel is driven by an electric spindle with a speed of 6000 - 10000 rpm. Since silicon carbide crystals have a high hardness second only to diamond, the cutting grinding wheel is customized with a special formed electroplated diamond grinding wheel. Different working conditions can be cut with different grinding wheel surfaces, and the outer circle and plane can be ground;

[0036] (2)The auxiliary grinding wheel is driven by a variable-frequency motor, and the power drives the main shaft to rotate through a multi-wedge belt. The rotational speed of the grinding wheel shaft in the working state is 3000 rpm. The cutting grinding wheel is customized into a plated diamond grinding wheel for machining the NOTCH groove of large-sized ingots with a size of more than 8 inches.

[0037] (3)The headstock is driven by a torque motor installed in the middle, with a compact structure. The rotational speed of the headstock is 300 rpm to drive the workpiece to rotate at a high speed. The clamping force for the workpiece installation is provided by the tailstock oil cylinder, and the magnitude of the acting force is adjustable. The workpiece is placed for grinding by the acting force applied by the ejector rods installed on the headstock and the tailstock.

[0038] Those skilled in the art can make various modifications and variations to the present invention. Provided that these modifications and variations are within the scope of the claims of the present invention and its equivalent technologies, these modifications and variations are still within the protection scope of the present invention patent.

[0039] The content not described in detail in the specification is the prior art well-known to those skilled in the art.

Claims

1. A multi-functional high-speed rounding grinder, characterized in that: It includes a bed body component, as well as a grinding wheel headstock component, a tailstock component, a crystal orientation detection mechanism, a headstock component, and a dimension detection mechanism installed on the bed body component. The bed body component includes a bed body, a workbench, a workpiece support, a rotating shaft, and a rack. Multiple feet are provided at the bottom of the bed body, and the installation surface of the bed body is ensured to be horizontal by adjusting the height of the feet. The upper surface of the workbench is used to install the headstock component and the tail component, and multiple installation holes for the tailstock component are drilled on its surface. The requirement of machining workpieces with different lengths can be met by moving the tailstock component. The workpiece support is installed on the workbench and is used to support the workpiece being machined; The grinding wheel headstock component includes a main grinding head forward and backward feed mechanism, a main grinding head, a main grinding head up and down feed mechanism, a sub-grinding head, a sub-grinding head forward and backward feed mechanism, and a left and right feed mechanism for the two grinding heads of the grinding wheel headstock. The main grinding head and the sub-grinding head are respectively installed on a support plate that allows forward and backward / left and right feeding. The main grinding head forward and backward feed mechanism is used to ensure the feed amount of the workpiece being machined. The main grinding head allows movement in three directions: left and right, up and down, and forward and backward. The main grinding head up and down feed mechanism switches the working state to grind the outer circle or the end face. The sub-grinding head performs high-speed grinding of the V-groove. The sub-grinding head feed mechanism is used to ensure the requirements of the groove depth and positional tolerance. The left and right feed mechanism for the two grinding heads of the grinding wheel headstock ensures the accuracy requirements within the grinding stroke range; The headstock component includes a headstock workpiece ejector rod, a headstock housing, a headstock rotating power shaft, a torque motor, and an angle rotation encoder. Angular contact bearings are installed at the front and rear of the headstock rotating power shaft, a torque motor is installed in the middle, and an angle rotation encoder is installed at the tail. The torque motor rotates the headstock rotating power shaft to drive the workpiece to rotate for grinding. The angle rotation encoder can determine the position of the torque motor's rotation at any time. When grinding the OFF reference surface, the angle rotation encoder stops the motor position according to the angle found by the crystal orientation locator detected by the crystal orientation detection mechanism for surface grinding.

2. The multifunctional high-speed rolling grinder according to claim 1, wherein: The bed body component is also provided with a rotating shaft and a rack. The rotating shaft is used to adjust the axial taper of the workpiece being machined to ensure the consistency of the diameter size. The rack is a part of the horizontal moving gear rack of the crystal orientation detection mechanism.

3. The multifunctional high-speed round grinding machine according to claim 1 or 2, characterized in that: The tailstock component includes a tailstock workpiece ejector rod, a telescopic mechanism, a tailstock housing, a bushing, a clamping oil cylinder, and a tailstock moving mechanism. The tailstock workpiece ejector rod cooperates with the headstock end ejector rod to clamp the workpiece for grinding. A clearance is provided between the bushing and the telescopic mechanism to ensure smooth telescoping of the mechanism without jamming. At the same time, the replacement of the bushing can protect the housing. The clamping oil cylinder provides an adjustable clamping force required for workpiece grinding. The tailstock moving mechanism is used to meet the required position changes within the length range of workpiece machining.

4. The multifunctional high-speed rolling grinder according to claim 1 or 2, characterized in that: The crystal orientation detection mechanism 4 includes a crystal orientation locator, a longitudinal feed mechanism, an installation base, and a horizontal feed mechanism. The crystal orientation locator determines the angle of the crystal line of the silicon carbide ingot through laser line detection, and rotates the workpiece to the required machining position for grinding through an angle encoder; The arrival and departure of the crystal orientation locator at the measurement point are completed by the longitudinal feed mechanism and the horizontal feed mechanism. Both move under servo control. The longitudinal movement is driven by a ball screw, and the horizontal movement is driven by a gear rack.

5. The multifunctional high-speed rounding grinding machine according to claim 1 or 2, characterized in that: The dimension detection mechanism includes a laser measuring head, a mounting base, a telescopic moving and feeding mechanism, and a cylinder. The dimension detection mechanism is installed on the headstock component. The laser measuring head measures the diameter and depth according to the displacement change amount by irradiating the surface of the workpiece with laser. The arrival and departure of the laser measuring head at the measurement point are driven by the cylinder to move the bracket along the linear guide pair. The laser measuring head detects the dimension data of the processed parts at each processing stage. The mounting base is fixed on the headstock box to limit the mounting measurement point.

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