System and method for wafer polishing and grinding

Abstract

A system for wafer polishing and grinding is provided, including a rack, and a loading unit, a transfer unit, a processing unit, and a pickup unit which are arranged on the rack. A first pickup portion of the pickup unit picks up a wafer from the loading unit, and a manipulator is driven by a mechanical arm to move to place the wafer in the transfer unit. The transfer unit is configured to position the wafer. Multiple pickup heads of a second pickup portion are configured to pick up multiple wafers positioned by the transfer unit, and the manipulator is driven by the mechanical arm to move to transfer the wafer to a processing position of the processing unit. The processing unit is configured to polish and grind the wafer. A method for wafer polishing and grinding is further provided.

What is claimed is: 
     
         1 . A system for wafer polishing and grinding, comprising:
 a rack;   a loading unit configured to store a plurality of wafers which are stacked;   a transfer unit configured to carry and position a single wafter of the stacked wafers;   a processing unit configured to polish and grind the wafers; and   a pickup unit;   wherein the loading unit, the transfer unit, the processing unit and the pickup unit are arranged on the rack;   the pickup unit comprising a mechanical arm arranged on the rack, and a manipulator connected to the mechanical arm, and the mechanical arm is capable of driving the manipulator to move in a space;   the manipulator comprises a first pickup portion, and a second pickup portion; the first pickup portion is of a flat structure to pick up a wafer stored by the loading unit, and is capable of picking up the wafers to be positioned in the transfer unit; the second pickup portion comprises a plurality of pickup heads to pick up the wafers positioned by the transfer unit and to place the plurality of wafers picked up by the pickup heads into processing positions of the processing unit; and after a processing of the wafers is completed, the second pickup portion is capable of removing the processed wafers.   
     
     
         2 . The system for wafer polishing and grinding according to  claim 1 , wherein the first pickup portion comprises an outer clamping plate, and an inner clamping plate slidably connected to the outer clamping plate, each of the outer clamping plate and the inner clamping plate having clamping grooves in fit with the wafers, the clamping grooves of the outer clamping plate are arranged opposite to the clamping grooves of the inner clamping plate, a clamping driver is connected to the inner clamping plate, and the outer clamping plate is a V-shaped plate with an opening facing away from the inner clamping plate. 
     
     
         3 . The system for wafer polishing and grinding according to  claim 1 , wherein the first pickup portion is of a Y-shaped plate structure, and a plurality of adhering elements are arranged on the first pickup portion to adhere to the wafers, the adhering elements communicate with an external adhering driver. 
     
     
         4 . The system for wafer polishing and grinding according to  claim 2 , wherein the second pickup portion comprises a mounting substrate, the mounting substrate and the first pickup portion are both connected to the mechanical arm, and the pickup heads are connected to the mounting substrate, a plurality of suction cups are arranged on each of the pickup heads, and the plurality of suction cups communicate with an external adhering driver, an end of the mounting substrate, connected to the pickup heads, is obliquely arranged. 
     
     
         5 . The system for wafer polishing and grinding according to  claim 4 , wherein the mounting substrate is of a star structure, and comprises a plurality of branch plates, the pickup heads being connected to the branch plates in a one-to-one correspondence. 
     
     
         6 . The system for wafer polishing and grinding according to  claim 1 , wherein the transfer unit comprises a positioning mechanism arranged on the rack, and comprises a flipping station capable of fixing the wafer and driving the wafer to flip, a plurality of positioning stations, and storage stations;
 each of the plurality of positioning stations comprises positioning pins uniformly distributed in a circumference, and detection sensors are further arranged on the positioning stations to detect whether the wafers are carried on the positioning stations and whether the wafers are inclined or deviated or not, the second pickup portion being capable of picking up the wafers on the positioning stations;   the storage stations are arranged below the positioning stations in a one-to-one correspondence, and are configured to store the wafers to be positioned, and the first pickup portion is capable of picking up the wafers on the storage stations.   
     
     
         7 . The system for wafer polishing and grinding according to  claim 6 , wherein the transfer unit further comprises a buffer mechanism comprising a buffer seat arranged on the rack, a motion mechanism, and a buffer table connected to the buffer seat through the motion mechanism, the motion mechanism being configured to drive the buffer table to move in a three-dimensional space;
 the buffer table comprises buffer stations, each of the buffer stations comprising a buffer yoke of a flat structure, and a buffer positioning block slidably connected to the buffer yoke, and a buffer driver is connected to the buffer positioning block, each of the buffer yoke and the buffer positioning block having buffer positioning slots in fit with the wafers, each of the buffer positioning slots is U-shaped, and openings of the buffer positioning slots of the buffer yoke are arranged opposite to openings of the buffer positioning slots of the buffer positioning block, the buffer positioning slots of the buffer yoke and the buffer positioning slots of the buffer positioning block cooperate to fix the wafers, the buffer stations and the storage stations are in a one-to-one correspondence to enable the buffer table to fix the wafers at the storage stations and drive the wafers to move to the positioning stations.   
     
     
         8 . The system for wafer polishing and grinding according to  claim 1 , further comprising:
 an unloading unit, and   an unloading docking unit, the unloading unit being configured to take out the wafers processed in the processing unit, and transfer the wafers to the unloading docking unit;   the unloading docking unit comprises a buffer water tank arranged adjacent to the processing unit, and an unloading water tank, the unloading unit being capable of removing the wafers from the processing unit and conveying the wafers into the buffer water tank, the unloading unit is further capable of transferring the wafers in the buffer water tank into the unloading water tank, and the unloading water tank is capable of being conveyed to a subsequent processing procedure.   
     
     
         9 . The system for wafer polishing and grinding according to  claim 1 , further comprising a control unit, wherein the loading unit, the transfer unit, the processing unit and the pickup unit are all in communication connection with the control unit;
 the processing unit further comprises a visual positioning mechanism configured to collect position information of the processing positions.   
     
     
         10 . A method for wafer polishing and grinding, wherein the system for wafer polishing and grinding according to  claim 1  is used, the method comprising:
 picking up a wafer from the loading unit by the first pickup portion of the pickup unit, and driving the manipulator by the mechanical arm to move to place the wafer in the transfer unit; 
 positioning the wafer by the transfer unit, picking up the plurality of wafers positioned by the transfer unit through the plurality of pickup heads of the second pickup portion, and driving the manipulator by the mechanical arm to move to transfer the plurality of wafers to the processing positions of the processing unit; 
 polishing and grinding the wafers through the processing unit. 
 
     
     
         11 . The system for wafer polishing and grinding according to  claim 3 , wherein the second pickup portion comprises a mounting substrate, the mounting substrate and the first pickup portion are both connected to the mechanical arm, and the pickup heads are connected to the mounting substrate, a plurality of suction cups are arranged on each of the pickup heads, and the plurality of suction cups communicate with the external adhering driver, an end of the mounting substrate, connected to the pickup heads, is obliquely arranged. 
     
     
         12 . The system for wafer polishing and grinding according to  claim 11 , wherein the mounting substrate is of a star structure, and comprises a plurality of branch plates, the pickup heads are connected to the branch plates in a one-to-one correspondence. 
     
     
         13 . The method for wafer polishing and grinding according to  claim 10 , wherein the first pickup portion comprises an outer clamping plate, and an inner clamping plate slidably connected to the outer clamping plate, each of the outer clamping plate and the inner clamping plate having clamping grooves in fit with the wafers, and the clamping grooves of the outer clamping plate are arranged opposite to the clamping grooves of the inner clamping plate, a clamping driver is connected to the inner clamping plate, and the outer clamping plate is a V-shaped plate with an opening facing away from the inner clamping plate. 
     
     
         14 . The method for wafer polishing and grinding according to  claim 10 , wherein the first pickup portion is of a Y-shaped plate structure, and a plurality of adhering elements are arranged on the first pickup portion to adhere to the wafers, the adhering elements communicate with an external adhering driver. 
     
     
         15 . The method for wafer polishing and grinding according to  claim 13 , wherein the second pickup portion comprises a mounting substrate, the mounting substrate and the first pickup portion are both connected to the mechanical arm, and the pickup heads are connected to the mounting substrate, a plurality of suction cups are arranged on each of the pickup heads, and the plurality of suction cups communicate with an external adhering driver, an end of the mounting substrate, connected to the pickup heads, is obliquely arranged. 
     
     
         16 . The method for wafer polishing and grinding according to  claim 15 , wherein the mounting substrate is of a star structure, and comprises a plurality of branch plates, and the pickup heads are connected to the branch plates in a one-to-one correspondence. 
     
     
         17 . The method for wafer polishing and grinding according to  claim 10 , wherein the transfer unit comprises a positioning mechanism arranged on the rack, and further comprises a flipping station, a plurality of positioning stations, and storage stations, the flipping station being capable of fixing the wafer and driving the wafer to flip;
 each of the plurality of positioning stations comprises positioning pins uniformly distributed in a circumference, and detection sensors are further arranged on the positioning stations to detect whether the wafers are carried on the positioning stations and whether the wafers are inclined or deviated or not, the second pickup portion being capable of picking up the wafers on the positioning stations;   the storage stations are arranged below the positioning stations in a one-to-one correspondence and are configured to store the wafers to be positioned, the first pickup portion being capable of picking up the wafers on the storage stations.   
     
     
         18 . The method for wafer polishing and grinding according to  claim 17 , wherein the transfer unit further comprises a buffer mechanism comprising a buffer seat arranged on the rack, a motion mechanism, and a buffer table connected to the buffer seat through the motion mechanism, the motion mechanism being configured to drive the buffer table to move in a three-dimensional space;
 the buffer table comprises buffer stations, each of the buffer stations comprises a buffer yoke of a flat structure, a buffer positioning block slidably connected to the buffer yoke, and a buffer driver connected to the buffer positioning block, each of the buffer yoke and the buffer positioning block having buffer positioning slots in fit with the wafers, each of the buffer positioning slots is U-shaped, and openings of the buffer positioning slots of the buffer yoke are arranged opposite to openings of the buffer positioning slots of the buffer positioning block, the buffer positioning slots of the buffer yoke and the buffer positioning slots of the buffer positioning block cooperate to fix the wafers, the buffer stations and the storage stations are in a one-to-one correspondence to enable the buffer table to fix the wafers at the storage stations and drive the wafers to move to the positioning stations.   
     
     
         19 . The method for wafer polishing and grinding according to  claim 10 , further comprising:
 an unloading unit, and   an unloading docking unit the unloading unit being configured to take out the wafers processed in the processing unit, and transfer the wafers to the unloading docking unit;   the unloading docking unit comprises a buffer water tank arranged adjacent to the processing unit, and an unloading water tank, the unloading unit being capable of removing the wafers from the processing unit and conveying the wafers into the buffer water tank, the unloading unit is further capable of transferring the wafers in the buffer water tank into the unloading water tank, and the unloading water tank is capable of being conveyed to a subsequent processing procedure.   
     
     
         20 . The method for wafer polishing and grinding according to  claim 10 , further comprising a control unit, wherein the loading unit, the transfer unit, the processing unit and the pickup unit are all in communication connection with the control unit;
 the processing unit further comprises a visual positioning mechanism configured to collect position information of the processing positions.