CN111805400A - polishing device - Google Patents

Abstract

The invention provides a polishing device, which is applied to wafers. The polishing device includes: an upper polishing disc, a lower polishing disc, a limit disc and a driving mechanism; the upper polishing disc is located on the side of the limiting disc facing a first direction, and the lower polishing disc It is located on the side of the limit disk facing the second direction, and the first direction and the second direction are two opposite directions; the rotation center of the lower polishing disk, the rotation center of the limit disk and the rotation center of the upper polishing disk are in the same rotation center The limit disk is used to carry the wafer, and the wafer passes through the limit disk along the first direction; the driving mechanism is used to respectively drive the upper polishing disk and the lower polishing disk to rotate relative to the rotation center line, so as to make the upper polishing disk and the lower polishing disk rotate. The discs are polished to opposite ends of the wafer, respectively. The present invention can simultaneously polish two opposite surfaces of the wafer.

Description

polishing device

technical field

The invention relates to the technical field of semiconductor production equipment, in particular to a polishing device.

Background technique

In the process of wafer production, it is usually necessary to perform chemical mechanical polishing on the backside of the wafer to remove particles on the backside of the wafer.

However, after chemical mechanical polishing is performed on the back side of the wafer, other equipment needs to be introduced to perform chemical mechanical polishing on the front side of the wafer, which not only prolongs the wafer manufacturing time, but also reduces the production efficiency of the wafer. The equipment used for wafer fabrication is also increased, thereby increasing the production cost of wafers.

SUMMARY OF THE INVENTION

In order to solve the above problems, the polishing device provided by the present invention can simultaneously polish two opposite surfaces of the wafer through the upper polishing disc and the lower polishing disc.

The present invention provides a polishing device, which is applied to wafers. The polishing device comprises: an upper polishing disc, a lower polishing disc, a limit disc and a driving mechanism;

The upper polishing disk is located on the side of the limit disk facing the first direction, the lower polishing disk is located on the side of the limit disk facing the second direction, and the first direction and the second direction are two opposite directions;

The rotation center of the lower polishing disk, the rotation center of the limiting disk and the rotation center of the upper polishing disk are on the same rotation center line;

The limiting disk is used for carrying the wafer, and the wafer penetrates the limiting disk along the first direction;

The driving mechanism is used for respectively driving the upper polishing disc and the lower polishing disc to rotate relative to the rotation center line, so that the upper polishing disc and the lower polishing disc respectively polish opposite ends of the wafer.

Optionally, the polishing device further comprises: a central rotating shaft;

The central rotating shaft penetrates the lower polishing disk, the limiting disk and the upper polishing disk, and the axis line of the central rotating shaft coincides with the rotation center line.

Optionally, the limiting disk is fixedly connected to the central rotating shaft, and both the upper polishing disk and the lower polishing disk are rotatably connected to the central rotating shaft.

Optionally, at least one through hole is formed on the surface of the limiting disk, the wafer passes through the limiting disk along the first direction through the at least one through hole, and the at least one through hole is located in the center the peripheral side of the shaft.

Optionally, a buffer ring is sleeved in the at least one through hole.

Optionally, the driving mechanism includes: a first driving member;

The first driving member is used to drive the limiting disk to rotate along the third direction;

The first driving member is also used for driving the limiting disk to rotate by a specified angle along the fourth direction.

Optionally, the driving mechanism further includes: a second driving member;

The second driving member is used to drive the upper polishing disc and the lower polishing disc to rotate in a third direction.

Optionally, the upper polishing plate includes: an upper pressure plate and an upper polishing pad;

The upper polishing pad is fixedly arranged on the side of the upper platen facing the second direction.

Optionally, the lower polishing disc includes: a lower pressing plate and a lower polishing pad;

The lower polishing pad is fixedly arranged on the side of the lower platen facing the first direction.

Optionally, the driving mechanism further comprises: a third driving member;

The third driving member is used for adjusting the relative distance between the upper polishing disc and the lower polishing disc.

The polishing device provided by the embodiment of the present invention can drive the upper polishing disk and the lower polishing disk to rotate through the driving mechanism, so that the upper polishing disk and the lower polishing disk can simultaneously polish the two opposite surfaces of the wafer, thereby saving the need for the wafer to be cleaned. The polishing time can reduce the investment of polishing equipment, which can improve the production efficiency of the wafer and reduce the production cost of the wafer; and the setting of the limit disk can limit the wafer, thus ensuring the polishing effect. uniformity.

Description of drawings

FIG. 1 is a cross-sectional structural view of a component of a polishing device between an upper platen and a lower platen according to an embodiment of the application;

FIG. 2 is a top view showing the positional relationship between the limiting disk and the lower polishing disk according to an embodiment of the present application.

reference number

100, wafer; 200, upper polishing plate; 201, upper platen; 202, upper polishing pad; 300, lower polishing plate; 301, lower platen; 302, lower polishing pad; 400, limit plate; 401, pass hole; 402, buffer ring; 500, center shaft.

Detailed ways

In order to make the purposes, 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 accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments It is only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

This embodiment provides a polishing apparatus, which is applied to a wafer 100. Referring to FIG. 1, the polishing apparatus includes: an upper polishing disc 200, a lower polishing disc 300, a limiting disc 400 and a driving mechanism. The upper polishing disk 200 is located on the side of the limiting disk 400 facing the first direction; the lower polishing disk 300 is located on the side of the limiting disk 400 facing the second direction; wherein the first direction and the second direction are two opposite directions Direction, in this embodiment, the first direction is an upward direction, and the second direction is a downward direction. The rotation center of the lower polishing disk 300, the rotation center of the limiting disk 400 and the rotation center of the upper polishing disk 200 are on the same rotation center line. The driving mechanism is used to respectively drive the upper polishing disk 200 and the lower polishing disk 300 to rotate relative to the rotation center line, so that the upper polishing disk 200 and the lower polishing disk 300 respectively polish opposite ends of the wafer 100 . The limiting plate 400 is used for carrying the wafer 100 .

The upper polishing plate 200 includes: an upper platen 201 and an upper polishing pad 202 . The upper polishing pad 202 is fixedly disposed on the side of the upper platen 201 facing the second direction. The lower polishing pad 300 includes: a lower pressing pad 301 and a lower polishing pad 302 . The lower polishing pad 302 is fixedly disposed on the side of the lower platen 301 facing the first direction.

The polishing device further includes: a central rotating shaft 500 . The central rotating shaft 500 runs through the lower platen 301 , the lower polishing pad 302 , the limiting plate 400 , the upper polishing pad 202 and the upper platen 201 along the first direction, and the axis of the central rotating shaft 500 coincides with the rotation centerline.

The driving mechanism includes: a first driving member, a second driving member and a third driving member. The first driving member is used to drive the limiting disk 400 to rotate in the third direction; the second driving member is used to drive the upper polishing disk 200 and the lower polishing disk 300 to rotate in the third direction; the third driving member is used to adjust the upper polishing disk The relative distance between the optical disc 200 and the lower polishing disc 300 . By disposing the first driving member, when the upper polishing pad 202 and the lower polishing pad 302 polish the wafer 100 at the same time, the limiting disk 400 can be driven to rotate in the third direction, which can further improve the uniformity of the wafer 100 after polishing.

In this embodiment, the third direction is the counterclockwise direction or the clockwise direction in the horizontal direction, and in this embodiment, the third direction is the counterclockwise direction; The lower polishing disc 300 is rotatably connected with the central rotating shaft 500; the first driving member is a servo motor, and the output shaft of the servo motor is fixedly connected with one end of the central rotating shaft 500, so that the first driving member drives the central rotating shaft 500 to rotate along the third direction, That is, the central rotating shaft 500 can drive the limiting disk 400 to rotate in the third direction; the second driving member can be a pulley driving assembly or a gear driving assembly. In this embodiment, the second driving member is a The upper pressure plate 201 and the lower pressure plate 301 can be driven to rotate in the third direction by the conveyor belt; the third driving member can be a lifting hydraulic cylinder or a telescopic electric rod. In this embodiment, the third driving member is a lifting hydraulic cylinder, and the lifting hydraulic cylinder The lifting rod is fixedly connected with the upper pressure plate 201, and the upper pressure plate 201 and the upper polishing pad 202 are slidingly connected with the central rotating shaft 500 along the first direction and the second direction. The lifting hydraulic cylinder can adjust the upper polishing by driving the lifting rod to move up and down. The relative distance between the pad 202 and the lower polishing pad 302 enables the upper pad 202 and the lower polishing pad 302 to continuously polish the wafer 100 by moving the upper platen 201 downward during the polishing process.

Referring to FIG. 2 , at least one through hole 401 is formed on the surface of the limiting disk 400 , and the wafer 100 penetrates the limiting disk 400 in the first direction through the at least one through hole 401 . In this embodiment, the number of the through holes 401 is four, and the four through holes 401 are symmetrically arranged on the peripheral side of the central rotating shaft 500 . Each through hole 401 is sleeved with a buffer ring 402 . The buffer ring 402 is fixedly connected with the limit plate 400 . The buffer ring 402 is used to buffer the thrust force exerted by the limit ring on the wafer 100 to prevent the edge of the wafer 100 from being damaged. ; A wafer 100 is placed in each buffer ring 402, and the wafer 100 is clamped with the limit plate 400 through the buffer ring 402, or used to increase the stability of the wafer 100 in the through hole to prevent the wafer 100 from being thrown A limit ring is removed, so that the polishing device can perform double-sided polishing on the four wafers 100 at the same time, which further improves the polishing efficiency of the polishing device. The thickness of the limiting disk 400 is smaller than the target thickness of the final polishing of the wafer 100 , so that friction between the limiting disk 400 and the upper polishing pad 202 or/and the lower polishing pad 302 can be avoided during the polishing process.

The polishing apparatus further includes: at least one robot, the robot is used for mounting the wafer 100 on the limiting disk 400 and for unloading the polished wafer 100 from the limiting disk 400 . The first driving member is also used to drive the limiting disk 400 to rotate by a specified angle along the fourth direction, the fourth direction is the counterclockwise direction or the clockwise direction in the horizontal direction, and the fourth direction in this embodiment is the counterclockwise direction; The mounting and unmounting of the wafer 100 can be facilitated. In this embodiment, the number of manipulators is one, and the first driving member can intermittently drive the limiting disk 400 to rotate 90 degrees in the third direction. In this way, during the process of mounting the wafers 100 , each wafer 100 is mounted. Into a through hole 401, the first driving member drives and drives the limit disk 400 to rotate 90 degrees in the third direction, so there is no need for the manipulator to rotate around the limit disk 400 to find the through hole 401 where the wafer 100 is not placed. The next wafer 100 may be placed at the position where the previous wafer 100 was placed, so that the mounting efficiency of the wafer 100 can be improved. The same is true in the process of unloading the wafer 100 , which is not repeated here.

When the number of manipulators is two, the first driving member can intermittently drive the limiting disk 400 to rotate 180 degrees in the third direction, so that the two manipulators can simultaneously mount or unload the wafer 100 .

The polishing device has a simple structure. The upper polishing disk 200 and the lower polishing disk 300 are driven to rotate by the driving mechanism, so that the upper polishing disk 200 and the lower polishing disk 300 simultaneously polish the two opposite surfaces of the wafer 100 , that is, the front surface of the wafer 100 is polished. During polishing, the particles on the backside of the wafer 100 can also be removed, thereby saving the time for polishing the wafer 100, reducing the investment in polishing equipment, and reducing the probability of defocusing of the wafer 100, thereby improving the efficiency of the wafer 100. The production efficiency of the circle 100 reduces the production cost of the wafer 100 and improves the polishing quality; and the setting of the limiting disk 400 can limit the wafer 100, thereby ensuring the uniformity of polishing.

In an optional embodiment, the limit plate 400 is rotatably connected to the central shaft 500, and the first driving member may be a pulley driving assembly or a gear driving assembly. In this embodiment, the first driving member is a pulley driving member, The pulley driving member can drive the limiting disk 400 to rotate in the third direction through the conveyor belt.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical scope disclosed by the present invention can easily think of changes or substitutions. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims (10)

1. A polishing device, applied to a wafer, wherein the polishing device comprises: an upper polishing disc, a lower polishing disc, a limit disc and a drive mechanism; The upper polishing disk is located on the side of the limit disk facing the first direction, the lower polishing disk is located on the side of the limit disk facing the second direction, and the first direction and the second direction are two opposite directions; The rotation center of the lower polishing disk, the rotation center of the limiting disk and the rotation center of the upper polishing disk are on the same rotation center line; The limiting disk is used for carrying the wafer, and the wafer penetrates the limiting disk along the first direction; The driving mechanism is used to respectively drive the upper polishing disk and the lower polishing disk to rotate relative to the rotation center line, so that the upper polishing disk and the lower polishing disk respectively polish the opposite ends of the wafer . 2. The polishing device according to claim 1, wherein the polishing device further comprises: a central rotating shaft; The central rotating shaft penetrates the lower polishing disk, the limiting disk and the upper polishing disk, and the axis line of the central rotating shaft coincides with the rotation center line. 3 . The polishing device according to claim 2 , wherein the limiting disk is fixedly connected to the central rotating shaft, and the upper polishing disk and the lower polishing disk are both rotatably connected to the central rotating shaft. 4 . 4 . The polishing device according to claim 2 , wherein at least one through hole is formed on the surface of the limiting disk, and the wafer passes through the limiting plate along the first direction through the at least one through hole. 5 . and the at least one through hole is located on the peripheral side of the central rotating shaft. 5 . The polishing device according to claim 4 , wherein a buffer ring is sleeved in the at least one through hole. 6 . 6. The polishing device according to claim 1, wherein the driving mechanism comprises: a first driving member; The first driving member is used to drive the limiting disk to rotate along the third direction; The first driving member is also used for driving the limiting disk to rotate by a specified angle along the fourth direction. 7. The polishing device according to claim 1, wherein the driving mechanism further comprises: a second driving member; The second driving member is used to drive the upper polishing disc and the lower polishing disc to rotate in a third direction. 8. The polishing device according to claim 1, wherein the upper polishing disc comprises: an upper pressure plate and an upper polishing pad; The upper polishing pad is fixedly arranged on the side of the upper platen facing the second direction. 9. The polishing device according to claim 1, wherein the lower polishing disc comprises: a lower pressing plate and a lower polishing pad; The lower polishing pad is fixedly arranged on the side of the lower platen facing the first direction. 10. The polishing device according to claim 1, wherein the driving mechanism further comprises: a third driving member; The third driving member is used for adjusting the relative distance between the upper polishing disc and the lower polishing disc.

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