CN112847141A

CN112847141A - Semiconductor wafer planarization system and use method

Info

Publication number: CN112847141A
Application number: CN202110097029.6A
Authority: CN
Inventors: 邓筑蓉
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-10-31
Filing date: 2019-10-31
Publication date: 2021-05-28
Also published as: CN110712131A; CN110712131B

Abstract

The invention discloses a semiconductor wafer flattening system and a using method thereof, the structure of which comprises a control panel, a device shell, a signal lamp, a working cabin and a flat grinding device, and the semiconductor wafer flattening system is characterized in that: the flat grinding device is positioned at the lower end of one side of the working cabin, which is provided with the signal lamp, and is embedded into the working cabin, the flat grinding device and the working cabin are fixedly connected in a mechanical welding mode, the signal lamp is vertical to the surface of the upper end of the working cabin and is movably connected with the working cabin, and the device shell and the working cabin are of an integrated structure which is connected left and right, so that the flat grinding device has the beneficial effects that: through the cooperation of sweeper and stopper to the motion trend of flowing water is set up to the arc post, cooperates the stagnant flow effect that the rim plate of the spiral plate body of end to end provided, comes the set waste material, uses simultaneously that the shape can become soft cushion compression deformation and transversely arranged's tapetum structure to collude and lead surplus waste material, gets into inside the feed frame, and the circulation is reciprocal, reaches not waiting to grind the remaining waste material that flies out of surface, and the flatness control of wafer is guaranteed to very big degree.

Description

Semiconductor wafer planarization system and use method

The invention relates to a divisional application of semiconductor wafer planarization equipment, which is filed as 31.10.2019 and is named as CN 201911055412.4.

Technical Field

The present invention relates to the field of semiconductors, and more particularly, to a semiconductor wafer planarization system and a method of using the same.

Background

The wafer refers to a silicon wafer used for manufacturing a silicon semiconductor integrated circuit, and in the processing process, the purpose of use needs to be achieved through various processing technologies, wherein the flatness control of the wafer is to process the wafer through a mechanochemical grinding mode, and the flatness is crucial to the use of a finished product, when the current semiconductor wafer flattening equipment is used for flattening process, the polishing operation is usually carried out by matching a grinding cutter which is flattened vertically downwards with pressure, and rotating as power through the cooling of grinding fluid, but the wafer has the following defects:

carry out the back of face through grinding cutter and carrier, the cutter is through the easy collapse of wafer carrier surface atress behind, cause the back of having fritter or likepowder granule departure, at present wash and grind the work simultaneously with the lapping liquid again, but have certain rotatory traction force easily to be drawn into the waste material at the rotatory in-process of cutter, because the waste material is mostly the polyhedron, scrape the surface of flower wafer carrier easily in following the rotation of cutter, thereby influence the surface flatness of wafer carrier, reduce the rate of utilization of wafer.

Disclosure of Invention

Aiming at the defects of the prior art, the invention is realized by the following technical scheme: a semiconductor wafer planarization system and a using method thereof structurally comprise a control panel, a device shell, a signal lamp, a working cabin and a flat grinding device, and are characterized in that: the flat grinding device is located at the lower end of one side, provided with the signal lamp, of the working cabin and is embedded into the working cabin, the flat grinding device and the working cabin are fixedly connected in a mechanical welding mode, the signal lamp is perpendicular to the upper end surface of the working cabin and is movably connected with the working cabin, the device shell and the working cabin are of an integrated structure which is connected in a left-right mode, and the device shell is of a rectangular block structure and is provided with an embedded control panel on the front end face of the device shell.

The flat grinding device is further optimized to be provided with a grinding wheel device, an assembly plate, a sliding groove, an oil hydraulic cylinder and a fixing frame, wherein the grinding wheel device is vertically installed at one end, provided with the fixing frame, of the upper end face of the assembly plate, the sliding groove and the grinding wheel device are installed on the left side and the right side of the end face of the assembly plate in a relative position relation and are in an integrated structure with the assembly plate, the oil hydraulic cylinder and the sliding groove are perpendicular to each other and are in clearance fit connection with the sliding groove through a sliding block below a shell of the oil hydraulic cylinder, the fixing frame is located between the grinding wheel device and the oil hydraulic cylinder and is fixedly connected with the oil hydraulic cylinder in a mechanical welding mode, a foldable pipeline structure is arranged on the fixing frame, and grinding fluid can be.

As a further optimization of the invention, the grinding wheel device is provided with a support, a grinding panel, a flange, a sweeper and a limiter, wherein the support is positioned on an outer arc surface of the flange and forms an integrated structure with the flange in a mechanical welding mode and is fixedly connected with the support, the limiter is inserted into a gap between the grinding panel and the grinding panel, the sweeper is attached to the inner end surface of the limiter, the surface of the grinding panel which is an arc rectangular block body is provided with a rough convex structure, and the grinding panel is positioned at one end of the support, which is far away from the flange.

As a further optimization of the sweeper, the sweeper is provided with a movable device, a spring wheel, a limiting block and a supporting block, the supporting block is fixedly connected with the limiting block, the spring wheel is positioned between the limiting block and the supporting block and is fixedly connected with the limiting block through a plate body in a welding mode, the movable device wraps the outer end face of the spring wheel and is in clearance fit connection with the spring wheel in a surface-to-surface contact mode, the supporting block is a special-shaped structure formed by combining a rectangular block structure and an oblique triangular structure, and the supporting block is positioned on the right side of the limiting block and is parallel to the limiting block in the left-right direction.

As a further optimization of the invention, the movable device is provided with a through hole column, a wedge block, a plush layer and a cushion block, wherein the wedge block is positioned on the upper end face of the through hole column, the wedge block and the wedge block are mutually vertical and are mechanically welded with the through hole column to form an integrated structure, the soft cushion block is mechanically connected with the wedge block, the plush layer is flatly laid on the upper surface of the soft cushion block, the wedge block and the soft cushion block are mechanically welded to form an integrated structure, the plush layer is in a rectangular transverse row and is provided with a rough plush special-shaped structure at one end, the soft cushion block is in a 7-shaped folded plate structure and is provided with a round ball cushion structure at one end, and the soft cushion block is positioned on one side, far away.

As a further optimization of the invention, the limiter is provided with a wheel disc, an arc-shaped column, a feeding frame, a baffle plate and a column body, wherein the arc-shaped column surrounds and is attached to one side, far away from the column body, of the end surface of the feeding frame, the column body is vertically embedded into the feeding frame and is welded with the feeding frame to form an integrated structure, the wheel disc is wound and attached to the arc-shaped end surface of the column body and is fixedly connected with the column body in a mechanical welding mode, the baffle plate is fixedly connected with the wheel disc, the arc-shaped column is of a rectangular block structure with an arc inclined surface on one side, and the arc-shaped column and the feeding frame form the integrated.

As a further optimization of the invention, the wheel disc is of an elliptical head-tail connected single-face thin plate structure, and is arranged in the center of the through hole of the feeding frame.

Advantageous effects

The invention relates to a semiconductor wafer flattening system and a using method thereof, wherein when flattening equipment works, raw materials are fixedly arranged on a fixed frame in advance, and after a high-pressure oil body is pressed into an oil pressure cylinder for fastening, the raw materials arranged above the fixed frame can be well matched with the grinding requirement to perform transverse displacement through the transverse movability of a chute, after the raw materials are assembled, a motor is started, after the raw materials are fixed through a flange and inherit the power transmitted by the motor, a grinding wheel device starts to work, an arc grinding panel is used for contacting the grinding surface of the raw materials to be ground, a pipeline on the fixed frame is adjusted to a proper angle, grinding fluid starts to be output, then the flying waste materials ground through the grinding panel in point contact are matched with an arc surface on an arc column to enable the water flow to have a certain flowing trend, so that the grinding fluid mixed with the waste materials flows into the feeding frame, and the rim plate of spiral winding on the cylinder is certain tiltability for the inward has, rivers get into the back along the rim plate, because the rim plate head and the tail link to each other, and rotatory centrifugal force that brings only can say that the waste material is thrown away and hugs closely on the plate face of rim plate, thereby prevent the backward flow outflow of waste material, simultaneously grind the panel past back, what the trail comes is the soft cushion on the activity ware, receiving horizontal extrusion force, the spring wheel pulls back the wedge with the tensile force of spring, and the soft cushion of top also can receive the block of pressure formation face bodily form, sweep remaining waste material inside the feeding frame, the fine hair on the fine hair layer of the same year rear side, can clip the waste material, and because softer texture, can not exert pressure, the injury of waste material to waiting to grind the surface has been avoided, the flatness of improvement wafer of very big limit.

Compared with the prior art, the invention has the following advantages:

through the cooperation of sweeper and stopper to the motion trend of flowing water is set up to the arc post, cooperates the stagnant flow effect that the rim plate of the spiral plate body of end to end provided, comes the set waste material, uses simultaneously that the shape can become soft cushion compression deformation and transversely arranged's tapetum structure to collude and lead surplus waste material, gets into inside the feed frame, and the circulation is reciprocal, reaches not waiting to grind the remaining waste material that flies out of surface, and the flatness control of wafer is guaranteed to very big degree.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic diagram of a semiconductor wafer planarization system and method of use according to the present invention.

FIG. 2 is a schematic diagram of a planarization system and a planarization apparatus using the same.

FIG. 3 is a schematic diagram of a polishing wheel apparatus and a semiconductor wafer planarization system using the same.

FIG. 4 is an enlarged structural view of a grinding wheel device A of the semiconductor wafer planarization system and the method of using the same according to the present invention.

FIG. 5 is a schematic diagram of the oscillating displacement structure of the sweeper of the semiconductor wafer planarization system and method of use of the present invention.

FIG. 6 is a schematic diagram of a semiconductor wafer planarization system and a method for using the same.

FIG. 7 is a schematic diagram of a semiconductor wafer planarization system and a method of using a stopper according to the present invention.

In the drawing, a control panel-1, a device shell-2, a signal lamp-3, a working cabin-4, a flat grinding device-5, a grinding wheel device-51, an assembly plate-52, a chute-53, an oil hydraulic cylinder-54, a fixed frame-55, a bracket-a, a grinding panel-b, a flange-c, a sweeper-d, a stopper-e, a movable device-d 1, a spring wheel-d 2, a stopper-d 3, a supporting block-d 4, a through hole column-d 11, a wedge-shaped block-d 12, a plush layer-d 13, a cushion block-d 14, a wheel disc-e 1, an arc column-e 2, a feeding frame-e 3, a baffle-e 4 and a column-e 5.

Detailed Description

In order to make the technical means, the original characteristics, the achieved purposes and the effects of the invention easy to understand, the following description and the accompanying drawings further illustrate the preferred embodiments of the invention.

Examples

Referring to fig. 1-7, the present invention provides a semiconductor wafer planarization system and a method of using the same, the structure of which includes a control board 1, a device housing 2, a signal lamp 3, a work chamber 4, and a flat polishing device 5, wherein: the flat grinding device 5 is positioned at the lower end of one side of the working cabin 4, provided with the signal lamp 3, of the working cabin 4 and is embedded into the working cabin 4, the flat grinding device 5 is fixedly connected with the working cabin 4 in a mechanical welding mode, the signal lamp 3 is perpendicular to the upper end surface of the working cabin 4 and is movably connected with the working cabin 4, the device shell 2 and the working cabin 4 are of an integrated structure which is connected in a left-right mode, the device shell 2 is of a rectangular block structure, an embedded control panel 1 is arranged on the front end face of the device shell 2, the flat grinding device 5 is provided with a grinding wheel device 51, an assembling plate 52, a sliding groove 53, an oil hydraulic cylinder 54 and a fixing frame 55, the grinding wheel device 51 is vertically arranged at one end of the assembling plate 52, the sliding groove 53 and the grinding wheel device 51 are arranged on the left side and the right side of the end face of the assembling plate 52 in a relative position relationship and are integrated with the assembling plate The grinding wheel device 51 is provided with a support a, a grinding panel b, a flange c, a sweeper d and a limiter e, the support a is positioned on the outer side arc surface of the flange c and forms an integrated structure with the flange c in a mechanical welding mode and is fixedly connected with the support a, the limiter e is inserted and installed in a gap between the grinding panel b and the grinding panel b, the sweeper d is attached to the inner side end surface of the limiter e, the surface of the grinding panel b which is an arc rectangular block is provided with a rough convex structure, and the grinding panel b is positioned at one end of the support a away from the flange c, the sweeper d is provided with a movable device d1, a spring wheel d2, a limit block d3 and a support block d4, the support block d4 is fixedly connected with a limit block d3, the spring wheel d2 is positioned between a limit block d3 and a support block d4 and is fixedly connected with a limit block d3 in a plate welding mode, the movable device d1 wraps the outer side end face of the spring wheel d2 and is in clearance fit connection with the spring wheel d2 in surface-to-surface contact, the support block d4 is a special-shaped structure formed by combining a rectangular block structure and an oblique triangular structure, the support block d4 is positioned on the right side of the limit block d3 and is parallel to the left side and the right side, cleaned blanking can stably enter the feeding frame e3 through the triangular structure at the front end, the movable device d1 is provided with a through hole column d11, a wedge block d12, a wedge 12 and a wedge 4, The plush layer d13 and the cushion block d14, the wedge-shaped block d12 is positioned on the upper side end face of the through hole column d11, the two are mutually vertical and are mechanically welded with the through hole column d11 to form an integrated structure, the soft cushion block d14 is mechanically connected with the wedge-shaped block d12, the plush layer d13 is flatly laid on the upper side surface of the soft cushion block d14, the two are mechanically welded to form the integrated structure, the plush layer d13 is rectangular and is transversely arranged, one end of the plush layer is provided with a rough and special-shaped plush structure, the soft cushion block d14 is folded into a 7-shaped plate body structure, one end of the soft cushion body is provided with a round ball, the soft cushion block d14 is positioned on one side of the upper end face of the wedge-shaped block d12, which is far away from the through hole column d11, the flat structure formed by the compression deformation of the round ball structure can effectively concentrate and collect waste materials, fine particles can be swept twice by the plush, the limiter e is provided with a wheel disc e1, an arc-shaped column e2, a feeding frame e3, a baffle plate e4 and a cylinder e5, the arc-shaped column e2 is attached to one side, far away from the cylinder e5, of the end face of the feeding frame e3 in an encircling manner, the cylinder e5 is vertically embedded into the feeding frame e3 and is welded with the feeding frame e3 to form an integrated structure, the wheel disc e1 is wound and attached to the arc-shaped end face of the cylinder e5 and is fixedly connected with the cylinder e5 in a mechanical welding manner, the baffle plate e4 is fixedly connected with the wheel disc e1, the arc-shaped column e2 is a rectangular block structure with an arc-shaped inclined plane on one side, the arc-shaped column e2 and the feeding frame e3 form the integrated structure in a mechanical welding manner, potential energy formed by the inclined plane can fall from a place ground in the front direction and has a certain displacement tendency, so that the collection and integration can be carried out, and the prevention of the damage to the flatness can, the central authorities of feed frame e3 through-hole are located to rim plate e1, when rotating through spiral end to end's structure, block the waste material with the upper surface body to prevent the backward flow output of waste material and influence the harm of equipment to the wafer.

When the flattening device works, raw materials are fixedly arranged on a fixed frame 55 in advance, high-pressure oil bodies are pressed into an oil pressure cylinder 54 for fastening, the raw materials arranged above the fixed frame 55 can be well matched with grinding needs to be transversely displaced through the transverse mobility of a sliding groove 53, after the flattening device is assembled, a motor is started, after the raw materials are fixed through a flange c and power transmitted by the motor is inherited, a grinding wheel device 51 starts to work, an arc-shaped grinding panel b contacts a grinding surface of the raw materials to be ground, a pipeline on the fixed frame 55 is adjusted to a proper angle, grinding fluid starts to be output, the flying waste materials are ground through the grinding panel b in point contact, the waste materials are enabled to have a certain flowing trend through the flowing of the grinding fluid through the arc-shaped surface on an arc-shaped column e2, and the grinding fluid with the waste materials is enabled to flow into a feeding frame e3, and the wheel disc e1 spirally wound on the cylinder e5 has a certain inward inclination, after water flow enters along the wheel disc e1, because the wheel disc e1 is connected end to end, the centrifugal force caused by rotation can only throw the waste out to be tightly attached to the plate surface of the wheel disc e1, so that backflow and outflow of the waste are prevented, meanwhile, after the grinding panel b passes through, the soft cushion block d14 on the movable device d1 follows, when the grinding panel b receives transverse extrusion force, the spring wheel d2 pulls the wedge-shaped block d12 back by the tensile force of the spring, the upper soft cushion block d14 is pressed to form a block body in a plane shape, the residual waste is swept into the feeding frame e3, fluff on the fluff layer d13 at the back side of the same age can clamp the waste, and because of soft texture, pressure cannot be applied, the damage of the waste to the surface to be ground is avoided, and the flatness of the wafer is greatly improved.

The invention solves the problem that after the surface of a grinding cutter is contacted with a carrier, the surface of the wafer carrier is easy to collapse due to the stress of the cutter after passing through the grinding cutter, so that small or powdery particles fly out, the grinding fluid is used for washing and grinding at the same time at present, but a certain rotary traction force is easy to roll in waste materials in the rotating process of the cutter, as the waste materials are mostly polygonal, the surface of the wafer carrier is easy to scrape in the rotating process of the cutter, thereby influencing the surface flatness of the wafer carrier and reducing the utilization rate of wafers, the invention combines the components mutually, combines a sweeper and a limiter, uses the motion trend of flowing water due to arc columns to associate with the flow stopping function provided by a wheel disc of a spiral plate body connected at the head and the tail to collect the waste materials, and simultaneously uses a fluff layer structure with the shape which can be changed into a soft cushion block to be deformed and transversely arranged to hook and pull the residual waste materials, and the wafer enters the feeding frame to be circularly reciprocated, so that flying waste is not left on the surface to be ground, and the flatness control of the wafer is ensured to a great extent.

While there have been shown and described what are at present considered the fundamental principles of the invention, the essential features and advantages thereof, it will be understood by those skilled in the art that the present invention is not limited by the embodiments described above, which are merely illustrative of the principles of the invention, but rather, is capable of numerous changes and modifications in various forms without departing from the spirit or essential characteristics thereof, and it is intended that the invention be limited not by the foregoing descriptions, but rather by the appended claims and their equivalents.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a semiconductor wafer flattening equipment, its structure includes control panel (1), device casing (2), signal lamp (3), work cabin (4), flat grinder (5), its characterized in that:

the flat grinding device (5) is positioned at the lower end of one side of the working cabin (4) provided with the signal lamp (3) and is embedded into the working cabin (4), the flat grinding device and the working cabin are fixedly connected in a mechanical welding mode, the signal lamp (3) is perpendicular to the upper end surface of the working cabin (4) and is movably connected with the working cabin (4), the device shell (2) and the working cabin (4) are of an integrated structure which is connected in a left-right mode, and the device shell (2) is of a rectangular block structure, and an embedded control panel (1) is arranged on the front end face of the device shell (2);

the flat grinding device (5) is provided with a grinding wheel device (51), an assembling plate (52), a sliding chute (53), an oil hydraulic cylinder (54) and a fixing frame (55), the grinding wheel device (51) is vertically arranged at one end of the upper end surface of the assembly plate (52) provided with a fixing frame (55), the sliding grooves (53) and the grinding wheel device (51) are arranged on the left side and the right side of the end surface of the assembly plate (52) in a relative position relationship and are integrated with the assembly plate (52), the oil hydraulic cylinder (54) and the sliding chute (53) are mutually vertical and are connected with the sliding chute (53) in a clearance fit way through a sliding block below the shell of the oil hydraulic cylinder (54), the fixing frame (55) is positioned between the grinding wheel device (51) and the oil hydraulic cylinder (54) and is fixedly connected with the oil hydraulic cylinder (54) in a mechanical welding mode, and a foldable pipeline structure is arranged on the fixing frame (55);

grinding wheel device (51) is equipped with support (a), grinds panel (b), flange (c), sweeper (d), stopper (e), support (a) lie in the outside arc surface of flange (c) and constitute integrated structure through mechanical welding's mode with flange (c), grind panel (b) and support (a) fixed connection, stopper (e) alternate and install the clearance between grinding panel (b) and grinding panel (b), sweeper (d) depend on and install at stopper (e) medial surface, grinding panel (b) is equipped with coarse protruding structure for the surface of circular arc rectangle block.

2. The semiconductor wafer planarization apparatus of claim 1, wherein: the sweeper (d) is provided with a movable device (d1), a spring wheel (d2), a limiting block (d3) and a supporting block (d4), the supporting block (d4) is fixedly connected with the limiting block (d3), the spring wheel (d2) is located between the limiting block (d3) and the supporting block (d4) and fixedly connected with the limiting block (d3) in a plate body welding mode, the movable device (d1) wraps the outer side end face of the spring wheel (d2) and is connected with the spring wheel (d2) in a surface-face contact clearance fit mode, and the supporting block (d4) is of a rectangular block structure and an inclined triangular structure combined special-shaped structure.

3. The semiconductor wafer planarization apparatus of claim 2, wherein: the movable device (d1) is provided with a through hole column (d11), a wedge-shaped block (d12), a plush layer (d13) and a cushion block (d14), the wedge-shaped block (d12) is positioned on the upper side end face of the through hole column (d11), the wedge-shaped block and the through hole column (d11) are perpendicular to each other and are mechanically welded to form an integrated structure, the soft cushion block (d14) is mechanically connected with the wedge-shaped block (d12), the plush layer (d13) is flatly laid and mounted on the upper side surface of the soft cushion block (d14) in a mechanical welding mode to form the integrated structure, the plush layer (d13) is in a rectangular transverse row and is provided with a rough plush special-shaped structure at one end, and the soft cushion block (d14) is in a 7-shaped folded plate structure and is provided with a round spherical cushion structure.

4. The semiconductor wafer planarization apparatus of claim 1, wherein: stopper (e) are equipped with rim plate (e1), arc post (e2), feeding frame (e3), baffle (e4), cylinder (e5), arc post (e2) encircle to laminate in feeding frame (e3) terminal surface and keep away from one side of cylinder (e5), the inside of cylinder (e5) perpendicular embedding feeding frame (e3) is simultaneously with feeding frame (e3) welding constitution integrated structure, rim plate (e1) winding is pasted and is tightly adopted mechanical welding's mode fixed connection in the circular arc terminal surface of cylinder (e5) simultaneously with cylinder (e5), baffle (e4) and rim plate (e1) fixed connection, arc post (e2) has the rectangular block structure on circular arc inclined plane for one side.

5. The semiconductor wafer planarization apparatus of claim 1, wherein: the wheel disc (e1) is of an oval head-to-tail single-face thin plate structure.

6. The semiconductor wafer planarization system and method of use of any one of claims 1-5, wherein:

when the grinding machine works, raw materials are fixedly arranged on a fixed frame (55) in advance, and after a high-pressure oil body is pressed into the oil hydraulic cylinder 54 for fastening, the raw materials arranged above the fixed frame (55) can be well matched with the raw materials to be ground to be transversely displaced through the transverse movability of the sliding groove (53);

after assembly, starting the motor, and after the flange (c) is fixed and power transmitted by the motor is inherited, starting the grinding wheel device (51) to work to contact the raw material grinding surface to be ground by the arc grinding panel b;

the grinding fluid is output after the pipeline on the fixed frame (55) is adjusted to a proper angle, then the flying waste is ground through a grinding panel (b) in point contact, the flow of the grinding fluid is matched with the cambered surface on the upper arc column (e2) to enable the water flow to have a certain flow trend, so that the grinding fluid mixed with the waste flows into the feeding frame (e3), the wheel disc (e1) spirally wound on the cylinder (e5) has a certain inward inclination, after the water flow enters along the wheel disc (e1), the wheel disc (e1) is connected end to end, and the centrifugal force caused by rotation only throws the waste out to be tightly attached to the panel surface of the wheel disc (e1), so that the backflow of the waste is prevented;

meanwhile, after the grinding panel (b) passes through, the soft cushion block (d12) on the movable device (d1) follows, when the grinding panel receives transverse extrusion force, the spring wheel (d2) pulls the wedge block (d12) back by the tensile force of the spring, the upper soft cushion block (d2) is pressed to form a block body in a shape of a face, the residual waste is swept into the feeding frame (e3), and the fluff on the fluff layer (d2) on the back side of the same year can clamp the waste, and due to the soft texture, pressure cannot be applied, so that the damage of the waste to the surface to be ground is avoided, and the flatness of the wafer is improved to the maximum extent.