CN114473846A

CN114473846A - Wafer grinding device

Info

Publication number: CN114473846A
Application number: CN202011257802.2A
Authority: CN
Inventors: 申埈燮; 张月; 杨涛; 卢一泓; 刘青; 杨帆
Original assignee: Institute of Microelectronics of CAS; Zhenxin Beijing Semiconductor Co Ltd
Current assignee: Institute of Microelectronics of CAS; Zhenxin Beijing Semiconductor Co Ltd
Priority date: 2020-11-11
Filing date: 2020-11-11
Publication date: 2022-05-13
Anticipated expiration: 2040-11-11
Also published as: CN114473846B

Abstract

The invention provides a wafer grinding device, comprising: the grinding seat, the first driving shaft and the protective ring; the protective ring is sleeved on the peripheral side of the grinding seat, one end of the first driving shaft is fixedly connected with the grinding seat, and the protective ring is connected with the grinding seat or the first driving shaft; at least one push plate is fixedly arranged in the protective ring and is positioned on one side of the grinding seat away from the first driving shaft; the first driving shaft is used for driving the guard ring and the first driving shaft to rotate along a first rotating direction; the surface of the grinding seat far away from the first driving shaft is used for grinding the wafer; the first direction of rotation includes a component in a vertical direction. The invention can make full use of the grinding fluid.

Description

Wafer grinding device

Technical Field

The invention relates to the technical field of semiconductor processing, in particular to a wafer grinding device.

Background

In the process of polishing a wafer, the wafer is generally processed by spraying a polishing liquid onto a polishing table while polishing the wafer. But the polishing liquid will leave the polishing table as the polishing table rotates immediately after being sprayed onto the polishing table.

This results in a large amount of slurry not actually involved in the wafer polishing, i.e., being treated as waste, resulting in a waste of slurry.

Disclosure of Invention

In order to solve the problems, the wafer grinding device provided by the invention can effectively prevent the grinding fluid from flying out of the grinding seat under the action of centrifugal force by arranging the protective ring and the push plate, and enables the grinding fluid to be returned to the position for grinding the wafer, thereby improving the utilization rate of the grinding fluid and reducing the waste of the grinding fluid.

The invention provides a wafer grinding device, comprising: the grinding seat, the first driving shaft and the protective ring;

the protective ring is sleeved on the peripheral side of the grinding seat, one end of the first driving shaft is fixedly connected with the grinding seat, and the protective ring is connected with the grinding seat or the first driving shaft;

at least one push plate is fixedly arranged in the protective ring and is positioned on one side of the grinding seat away from the first driving shaft;

the first driving shaft is used for driving the guard ring and the first driving shaft to rotate along a first rotating direction;

the surface of the grinding seat far away from the first driving shaft is used for grinding the wafer;

the first direction of rotation includes a component in a vertical direction.

Optionally, the wafer polishing apparatus further comprises: a carrier;

the carrier is used for driving the wafer to be in contact with the grinding seat;

when the grinding table grinds the wafer, one end of the carrying piece, which is connected with the wafer, is positioned in the protective ring.

Optionally, the wafer polishing apparatus includes: at least one set of grinding modules, each set of grinding modules all includes: one said grinding cup, one said first drive shaft and one said guard ring;

in each two groups of grinding modules, the two first driving shafts are respectively positioned on one side of the corresponding grinding seat far away from the other grinding seat.

Optionally, the wafer polishing apparatus further comprises: the driving assembly is used for driving all the carriers to rotate;

the drive assembly is connected with all the carriers.

Optionally, the drive assembly comprises: a second drive shaft, a rotary drive member, at least two third drive shafts, and at least one reversing assembly;

the rotary driving piece is fixedly connected with one end of the second driving shaft and is used for driving the second driving shaft to rotate along a second rotation direction;

the other end of the second driving shaft is connected with the reversing assembly, one end of the third driving shaft is fixedly connected with one end, far away from the corresponding grinding seat, of the carrier, and the other end of the third driving shaft is connected with the reversing assembly;

the reversing assembly is used for driving the third driving shaft to rotate along the third rotating direction through the second driving shaft;

the third rotating direction and the first rotating direction are in the same plane, and the plane where the second rotating direction is located is intersected with the plane where the third rotating direction is located.

Optionally, in the case that the number of the reversing assemblies is at least two,

the second drive shaft includes: a first rotating shaft and at least one second rotating shaft;

one end of the first rotating shaft is connected with the rotary driving piece, the other end of the first rotating shaft is connected with one reversing component, and two ends of the second rotating shaft are respectively connected with the two reversing components.

Optionally, the commutation assembly comprises: the device comprises a shell, a first bevel gear and a second bevel gear;

the first bevel gear and the second bevel gear are both located in the machine shell, one end of the first rotating shaft is inserted into the machine shell and fixedly connected with the first bevel gear, one end of the third driving shaft is inserted into the machine shell and fixedly connected with the second bevel gear, and the first bevel gear is meshed with the second bevel gear.

Optionally, the reversing assembly further comprises: a third bevel gear;

the third bevel gear is located in the machine shell, and one end of the second rotating shaft is inserted into the machine shell and fixedly connected with the third bevel gear.

Optionally, the wafer polishing apparatus further comprises: at least one of the translational drive members is,

the at least one translation driving piece is connected with the first driving shaft and used for driving the grinding seat and the protection ring to move along the direction perpendicular to the plane where the first direction is located.

Optionally, when the guard ring is connected with the first driving shaft, an inner gear, an outer gear and a connecting gear are arranged on the inner side of the guard ring;

the inner gear, the outer gear and the connecting gear are all located on one side, facing the first driving shaft, of the grinding seat, the inner gear is fixedly connected with the protection ring, the first driving shaft penetrates through the outer gear and is fixedly connected with the outer gear, the connecting gear is located between the inner gear and the outer gear, and the connecting gear is meshed with the inner gear and the outer gear respectively.

The wafer grinding device provided by the embodiment of the invention can effectively prevent the grinding fluid from flying out of the grinding seat under the action of centrifugal force and gravity through the arrangement of the protective ring and the push plate, and the grinding fluid returns to the position for grinding the wafer from the upper part of the wafer under the driving of the push plate, so that the utilization rate of the grinding fluid is improved, and the waste of the grinding fluid is reduced.

Drawings

FIG. 1 is a schematic diagram of a wafer cleaning apparatus with a polishing table and a retaining ring shown in cross-section according to an embodiment of the present application;

FIG. 2 is an internal block diagram of a bottom reversing component of an embodiment of the present application;

FIG. 3 is an internal block diagram of an intermediate reversing component of an embodiment of the present application;

FIG. 4 is an internal block diagram of a top reversing assembly according to an embodiment of the present application;

fig. 5 is an internal structural view of a polishing module according to an embodiment of the present application.

Reference numerals

1. A grinding module; 11. a grinding seat; 111. a grinding disk; 112. a polishing pad; 12. a first drive shaft; 13. a guard ring; 14. pushing the plate; 15. a carrier; 2. a drive assembly; 21. a second drive shaft; 211. a first rotating shaft; 212. a second rotating shaft; 22. a rotary drive member; 23. a third drive shaft; 3. a commutation assembly; 31. a housing; 32. a first bevel gear; 33. a second bevel gear; 34. a third bevel gear; 41. an internal gear; 42. an outer gear; 43. a connecting gear; 5. a wafer.

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 only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The present embodiment provides a wafer polishing apparatus, and with reference to fig. 1, the wafer polishing apparatus includes: two sets of grinding modules 1 and a drive assembly 2 for driving all carriers 15 in rotation. Wherein each group of grinding modules 1 comprises: a grinding table 11, a first drive shaft 12, a guard ring 13 and a plurality of carriers 15; the carrier 15 is used for driving the wafer 5 to contact with the grinding seat 11 and driving the wafer 5 to rotate relative to the grinding seat 11; the first driving shaft 12 is used for driving the guard ring 13 and the first driving shaft 12 to rotate along the first rotating direction. In this embodiment, the carrier 15 is a suction cup.

In any group of grinding modules 1, the grinding seat 11 comprises: a polishing disk 111 and a polishing pad 112. Wherein, the polishing pad 112 is used for polishing the wafer 5; the protective ring 13 is sleeved on the peripheral side of the grinding disc 111; one end of the first driving shaft 12 is fixedly connected with the grinding seat 11; the polishing pad 112 is fixedly disposed on a side of the polishing disc 111 away from the first driving shaft.

In the present embodiment, the first rotation direction is a direction rotating perpendicular to the left-right direction; each group of grinding modules 1 comprises three carriers 15, the three carriers 15 are vertically arranged, and each carrier 15 adsorbs one wafer 5 for grinding; the protective ring 13 is fixedly connected with the grinding seat 11; a plurality of push plates 14 are fixedly arranged in the protective ring 13, and the push plates 14 are positioned on one side of the grinding pad 112 away from the grinding disc 111; the grinding pad 112 is vertically arranged, and the plurality of push plates 14 are all vertical to the grinding pad 112; one end of the carrier 15 is located within the guard ring 13 when the wafer 5 is being polished by the polishing station.

Through setting up guard ring 13 and push pedal 14 can prevent effectively that the lapping liquid from flying away from grinding seat 11 under the effect of centrifugal force and gravity to make the lapping liquid drive down at push pedal 14 from the top of wafer 5 come back to the position that wafer 5 ground again, thereby improved the utilization ratio of lapping liquid, reduced the waste of lapping liquid.

In two sets of grinding module 1, two first drive shafts 12 are located the corresponding one side that grinds seat 11 and keep away from another grinding seat 11 respectively, and two first drive shafts 12 keep away from the one end of corresponding grinding seat 11 and all fixedly are provided with driving motor, and driving motor is used for driving first drive shaft 12 to rotate, and corresponding driving motor's output shaft and corresponding first drive shaft 12 are with axle center fixed connection.

In the present embodiment, the driving assembly 2 includes: a second drive shaft 21, one rotary drive member 22, six third drive shafts 23 and three reversing assemblies 3. The three reversing assemblies 3 are vertically positioned between the two grinding tables, and the three reversing assemblies 3 are used for driving a third driving shaft 23 to rotate along a third rotating direction through a second driving shaft 21; the rotary drive member 22 is a rotary drive motor; the second drive shaft 21 includes: a first rotating shaft 211 and two second rotating shafts 212; one end of the first rotating shaft 211 is coaxially and fixedly connected with an output shaft of the rotary driving motor, and the output shaft of the rotary driving motor is vertically upward; the other end of the first rotating shaft 211 is connected with a reversing component 3, and two ends of two second rotating shafts 212 are respectively connected with two different reversing components 3; one end of the third driving shaft 23 is fixedly connected with one end of the carrier 15 far away from the corresponding grinding seat 11, and the other end of the third driving shaft 23 is connected with the reversing assembly 3; the third rotation direction is the same as the first rotation direction, and the plane of the second rotation direction is perpendicular to the plane of the third rotation direction.

Further, in connection with fig. 2, each commutation assembly 3 comprises: a housing 31, a first bevel gear 32 and two second bevel gears 33; both the first bevel gear 32 and the second bevel gear 33 are located within the housing 31.

In the embodiment, the first bevel gear 32 is arranged horizontally, the two second bevel gears 33 are arranged perpendicular to the first bevel gear 32 and opposite to each other, and the bottoms of the two second bevel gears 33 are meshed with the first bevel gear 32; one end of the first rotating shaft 211 is inserted into the housing 31 and fixedly connected with the first bevel gear 32, one end of the third driving shaft 23 is inserted into the housing 31 and fixedly connected with the second bevel gear 33, and the first bevel gear 32 is engaged with the second bevel gear 33.

Further, with reference to fig. 3 and 4, the reversing assembly 3 further includes: a third bevel gear 34. The third bevel gear 34 is located within the housing 31. In this embodiment, the reversing assemblies 3 at the upper and lower ends each include one third bevel gear 34, and the reversing assembly 3 in the middle includes two third bevel gears 34. In the reversing assembly 3 located below, the third bevel gear 34 is horizontally located above the first bevel gear 32 and is engaged with the tops of the two second bevel gears 33, the first rotating shaft 211 is vertically and fixedly connected with the first bevel gear 32, the bottom end of the second rotating shaft 212 is vertically inserted into the casing 31 and is fixedly connected with the third bevel gear 34, one end of each of the two third driving shafts 23 is vertically and fixedly connected with one of the second bevel gears 33, and the other end of each of the two third driving shafts 23 is vertically and fixedly connected with a corresponding carrier 15 in each of the two grinding modules 1.

The third bevel gear 34 is identical to the first bevel gear 32 in this embodiment, and both are identical gears. With reference to fig. 2 and 3, the structure of the reversing assembly 3 located at the middle position is substantially the same as that of the reversing assembly 3 located at the bottom end, except that: the bevel gear fixedly connected with the second rotating shaft 212 positioned below the reversing assembly 3 at the middle position is the third bevel gear 34. With reference to fig. 3 and 4, the machine-changing assembly in the top position is substantially identical in structure to the reversing assembly 3 in the middle, with the only difference that: the reversing assembly 3 at the top end position does not include a third bevel gear 34 which meshes with the top of the second bevel gear 33. Can make this wafer grinder grind a plurality of wafers 5 simultaneously through setting up switching-over subassembly 3, improve the efficiency of grinding greatly.

In this embodiment, the wafer polishing apparatus further includes: two translational drives. Wherein, two translation driving pieces respectively with corresponding driving motor fixed connection, and translation driving piece is used for driving corresponding grinding seat 11 and guard ring 13 and removes along left and right directions. In this embodiment, the translation drive comprises: support, slide and pneumatic cylinder. The hydraulic cylinder is fixedly connected with the support, a movable rod of the hydraulic cylinder is fixedly connected with the sliding plate, and the sliding plate is connected with the support in a sliding manner and is fixedly connected with the driving motor. The mounting and dismounting of the wafer 5 can be facilitated by the provision of a translation drive.

In an alternative embodiment, referring to fig. 5, when the guard ring 13 is connected to the first driving shaft 12, the inner side of the guard ring 13 is provided with an inner gear 41, an outer gear 42 and a connecting gear 43. The internal gear 41, the external gear 42 and the connecting gear 43 are all positioned on one side of the grinding base 11 facing the first driving shaft 12, the internal gear 41 is fixedly connected with the guard ring 13, the first driving shaft 12 penetrates through the external gear 42 and is fixedly connected with the external gear 42, the connecting gear 43 is positioned between the internal gear 41 and the external gear 42, and the connecting gear 43 is meshed with the internal gear 41 and the external gear 42 respectively. In the present embodiment, the number of the connecting gears 43 is four. The rotation speed of the protective ring 13 relative to the grinding seat 11 can be changed by arranging the internal gear 41, the external gear 42 and the connecting gear 43, so that the rotation speed of the protective ring 13 is less than that of the grinding seat 11, the grinding fluid moving to the upper part of the wafer 5 can fall and separate from the push plate 14 in enough time, and the high utilization rate of the grinding fluid is further ensured.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A wafer polishing apparatus, comprising: the grinding seat, the first driving shaft and the protective ring;

the first direction of rotation includes a component in a vertical direction.

2. The wafer polishing apparatus as set forth in claim 1, further comprising: a carrier;

3. The wafer polishing apparatus as set forth in claim 2, wherein the wafer polishing apparatus comprises: at least one set of grinding modules, each set of grinding modules all includes: one said grinding cup, one said first drive shaft and one said guard ring;

4. The wafer polishing apparatus as set forth in claim 3, further comprising: the driving assembly is used for driving all the carriers to rotate;

the drive assembly is connected with all the carriers.

5. The wafer polishing apparatus as set forth in claim 4 wherein the drive assembly comprises: a second drive shaft, a rotary drive member, at least two third drive shafts, and at least one reversing assembly;

6. The wafer polishing apparatus as set forth in claim 5, wherein in the case where the number of the reversing assemblies is at least two,

7. The wafer polishing apparatus of claim 6, wherein the reversing assembly comprises: the device comprises a shell, a first bevel gear and a second bevel gear;

8. The wafer polishing apparatus of claim 7, wherein the reversing assembly further comprises: a third bevel gear;

9. The wafer polishing apparatus as set forth in claim 1, further comprising: at least one of the translational drive members is,

10. The wafer polishing apparatus as set forth in claim 1, wherein an inner gear, an outer gear and a connecting gear are provided on an inner side of the guard ring when the guard ring is connected with the first driving shaft;