KR20070016649A - Wafer grinding apparatus and Wafer grinding method using the same - Google Patents

Abstract

A wafer polishing apparatus and a wafer polishing method using the same are provided. The provided wafer polishing apparatus includes a wheel body, a plurality of wheel blades provided on one side of the wheel body, and a wheel moving unit for reciprocating at least one of the wheel blades. Accordingly, according to the provided wafer polishing apparatus, the wafer is polished by using a plurality of wheel blades having different grain sizes or by polishing a wafer using a plurality of wheel blades of different materials. It is possible to quickly reduce the thickness of the chip while dramatically improving the surface roughness.

Description

Wafer grinding apparatus and wafer grinding method using the same {Wafer grinding apparatus and Wafer grinding method using the same}

1 is a side view showing an embodiment of a wafer polishing apparatus according to the present invention.

FIG. 2 is a plan view of the polishing head shown in FIG. 1 as viewed from the A direction. FIG.

3 is a cross-sectional view taken along the line II ′ of the polishing apparatus shown in FIG. 1.

4 is a cross-sectional view showing a state in which the second wheel blade is lowered by a predetermined distance in the polishing apparatus shown in FIG. 3.

FIG. 5 is a bottom view of the polishing wheel shown in FIG. 3 as viewed from the B direction. FIG.

Figure 6 is a bottom view of another embodiment of the abrasive wheel according to the present invention.

Figure 7 is a bottom view of a polishing wheel of another embodiment according to the present invention.

8 is a cross-sectional view showing a wheel moving unit of another embodiment according to the present invention.

9 is a cross-sectional view illustrating a state in which the second wheel blade is lowered by a predetermined distance by using the wheel moving unit shown in FIG. 8.

10 is a block diagram showing an embodiment of a wafer polishing method according to the present invention.

11 is a block diagram showing another embodiment of a wafer polishing method according to the present invention.

12 is a block diagram showing another embodiment of a wafer polishing method according to the present invention.

<Description of the symbols for the main parts of the drawings>

90 wafer

100: wafer polishing apparatus

120: polishing head

123: Wheel Clamp

127: Polishing Wheel

130: wheel moving unit

150: wafer chuck

The present invention relates to an apparatus and method for use in a semiconductor manufacturing process, and more particularly, to a wafer polishing apparatus for polishing the back side of a wafer and a wafer polishing method using the same.

Wafers used to make integrated circuits go through several stages of manufacturing, including diffusion, photography, etching and ion implantation. After such a manufacturing process, an electrical die sorting (EDS) process is performed to classify good and defective products by testing electrical characteristics and operating conditions of devices formed on the wafer. In addition, the device determined as a good product in the DS process is cut into a chip shape and is made into a finished product through an assembly process and a package process.

Among these processes, the wafer must have a sufficient thickness to prevent wafer breakage or surface damage during handling during the manufacturing and testing process. However, for the miniaturization and high integration of chip components, it is advantageous to have a thin wafer. Therefore, the thickness of the wafer is maintained above a certain size during the manufacturing and testing process, and a single type polishing wheel is used immediately after the cutting process before cutting the wafer for each chip for assembly and package. The backside of the wafer (opposite side of the surface on which the element is formed) is polished by using a wafer polishing apparatus having the same to reduce the thickness of the wafer to a very thin thickness. For example, the thickness of the wafer is maintained at about 750 μm during the manufacturing and testing process, and the thickness of the wafer is reduced to about 470 μm using the wafer polishing apparatus after the test process.

On the other hand, electronic products in which semiconductor chips are essentially used have become very small in size as their performance has recently been improved. Accordingly, requirements for semiconductor chips to be provided in electronic products are becoming more stringent. For example, a semiconductor chip used for an LCD, a smart card, or the like requires a thickness of about 150 μm, and its surface roughness requires less than 10 nm. Therefore, recently, in the wafer polishing apparatus, the polishing wheel for polishing the actual wafer is replaced with the polishing wheel having a finer surface, and then the wafer polishing process is performed.

However, in such a case, the chip thickness can be made very thin and the surface roughness can be polished to within 10 nm, but the wafer having a thickness of about 750 μm can be polished to about 150 μm with the above-described polishing wheel. It takes a long time, which leads to a decrease in productivity.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a wafer polishing apparatus and a wafer polishing method using the same, which can quickly reduce the thickness of a chip while significantly improving the surface roughness of the polished chip.

According to a first aspect of the present invention for implementing the above technical problem, a wheel body, a plurality of wheel blades provided on one side of the wheel body and polishing the wafer, and a wheel for reciprocating at least one of the wheel blades A wafer polishing apparatus including a moving unit is provided.

In one embodiment, the wheel blades may be provided below the wheel body. In this case, the wheel moving unit may lift at least one of the wheel blades.

In another embodiment, the wheel blades may be formed of a diamond material. In this case, the wheel blades may have particle sizes of different sizes. In addition, the wheel blades may be formed in a circular ring shape each having a different diameter. In this case, the wheel blades may be arranged in a concentric shape.

In another embodiment, the wheel blades may include a first wheel blade formed of a diamond material, and a second wheel blade formed of a nonwoven material. In this case, the first wheel blade may be formed in a circular ring shape, and the second wheel blade may be disposed inside the first wheel blade.

In another embodiment, the wheel blades may include a circular ring-shaped first wheel blade provided at the edge of the polishing wheel, and a second wheel blade disposed inside the first wheel blade. In this case, the first wheel blade and the second wheel blade may be formed of different materials.

On the other hand, the wheel moving unit is connected to one side of the one of the wheel blade, the bearing is provided on one side end of the connecting shaft, the connecting shaft is in contact with the bearing to move the predetermined distance reciprocating in the vertical direction of the connecting shaft It may include a cam, a rotating shaft connected to the cam, and a rotating motor for rotating the rotating shaft to reciprocate a predetermined distance while rotating the rotating shaft to reciprocate the cam. In this case, the wheel moving unit may further include a distance sensor for detecting the moving distance of the cam is located on one side of the rotary motor. The wheel moving unit may further include an elastic member for returning the connecting shaft moved by the cam to its original position.

In addition, the wheel moving unit may include a piston rod coupled to one side of any one of the wheel blades, and a cylinder connected to the piston rod to reciprocate the piston rod a predetermined distance.

According to a second aspect of the invention, there is provided a method of loading a wafer into a wafer chuck, a primary polishing step of polishing the wafer using a plurality of wheel blades, lowering some of the wheel blades, and lowering A wafer polishing method using a wafer polishing apparatus including a secondary polishing step of polishing a wafer with a wheel blade is provided.

The wheel blades may be formed of a diamond material. In this case, the wheel blades may have particle sizes of different sizes. In the second polishing step, the wafer may be polished with a wheel blade having the smallest particle size among the wheel blades.

In addition, the wheel blades may include a wheel blade formed of a diamond material and a wheel blade formed of a nonwoven material. In this case, in the second polishing step, the wafer may be finely polished with a wheel blade formed of a nonwoven material.

According to a third aspect of the present invention, there is provided a method of loading a wafer into a wafer chuck, a primary polishing step of polishing a wafer using any of a plurality of wheel blades, lowering another of the wheel blades, and There is provided a wafer polishing method using a wafer polishing apparatus including a secondary polishing step of polishing a wafer with a lowered wheel blade.

In this case, in the second polishing step, the wafer may be finely polished with a wheel blade having a particle size smaller than that of the first polishing step.

In addition, in the first polishing step, the wafer may be polished with a wheel blade formed of a diamond material, and in the second polishing step, the wafer may be finely polished with a wheel blade formed of a nonwoven material.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the scope of the invention to those skilled in the art will fully convey. Like numbers refer to like elements throughout.

1 is a side view showing an embodiment of a wafer polishing apparatus according to the present invention, FIG. 2 is a plan view of the polishing head shown in FIG. 1 viewed from the A direction, and FIG. Sectional view taken along the line I ′. 4 is a cross-sectional view illustrating a state in which the second wheel blade is lowered by a predetermined distance in the polishing apparatus shown in FIG. 3, and FIG. 5 is a bottom view of the polishing wheel illustrated in FIG. Is a bottom view showing a polishing wheel of another embodiment according to the present invention. 7 is a bottom view showing another embodiment of the abrasive wheel according to the invention, Figure 8 is a cross-sectional view showing a wheel moving unit of another embodiment according to the present invention, Figure 9 is a wheel shown in Figure 8 It is sectional drawing which shows the state which lowered the 2nd wheel blade the predetermined distance using the moving unit.

First, referring to FIGS. 1 to 5, the wafer polishing apparatus 100 according to an embodiment of the present invention is an apparatus for polishing the back surface of the wafer 90, that is, the surface opposite to the surface on which the device is formed, and is loaded from the outside. And a wafer chuck 150 to seat the wafer 90. At this time, the wafer 90 is loaded with the protection tape 95 such as UV tape attached to the surface where the device is formed, and the back side thereof, that is, the opposite side of the surface where the device is formed, faces the top of the wafer chuck 150. It is mounted on the upper surface of the wafer chuck 150 so as to. The wafer chuck 150 fixes the wafer 90 seated on the upper surface of the wafer chuck 150 by vacuum suction or the like. The wafer chuck 150 is rotatably installed. Thus, the wafer chuck 150 is self-rotated at a predetermined ALPM, for example, when the wafer 90 fixed thereon begins to be polished.

On the other hand, the polishing head 120 is provided on the top of the wafer chuck 150 to polish the back surface of the wafer 90 seated on the wafer chuck 150. The polishing head 120 is installed to move up and down a predetermined distance. Accordingly, when the wafer 90 is seated on the wafer chuck 150, the polishing head 120 is lowered by a predetermined distance from the top of the wafer chuck 150 to polish the wafer 90 on the wafer chuck 150.

Specifically, the polishing head 120 may include a polishing wheel 127 having a plurality of wheel blades provided thereon to polish the wafer 90, at least one of the wheel blades of the polishing wheel 127, or all of the wheel blades. Wheel moving units 130 and 230 for elevating the wheels, wheel clamps 123 for clamping the polishing wheels 127 on the top of the polishing wheels 127 to rotate the polishing wheels 127, and the wheel clamps 123. It includes a head motor 121 to rotate by a predetermined RMP.

The polishing wheel 127 is composed of a disk-shaped wheel body 124 and a wheel blade provided below the wheel body 124. The wheel body 124 is detachably mounted to the lower portion of the wheel clamp 123. Therefore, when a certain number of wafer polishing is performed, the user or the like replaces the polishing wheel 127 by detaching the wheel body 124 from the wheel clamp 123.

The wheel blades contact the back side of the wafer 90 and serve to directly polish the wafer 90. Accordingly, the wheel blades can be constructed and arranged in various forms.

In one embodiment, the wheel blades may be constructed and arranged as shown in FIG. 5. That is, the wheel blades include a circular ring shaped first wheel blade 125 provided at the bottom edge of the wheel body 124 and a circular ring shaped second wheel blade 126 disposed inside the first wheel blade 125. It can be composed of). In this case, the first and second wheel blades 125 and 126 may be formed of diamond materials having particle sizes of different sizes, respectively, and may be arranged in a concentric shape. For example, the particle size of the first wheel blade 125 may have 2000 mesh, and the particle size of the second wheel blade 126 may have 3000 mesh. In addition, the first wheel blade 125 and the second wheel blade 126 may be formed of different materials. For example, the first wheel blade 125 may be formed of a material that sinters diamond fine particles and resin, that is, a diamond material, and the second wheel blade 126 may be a material that compresses polyethylene fiber or the like into a polymer, It may be formed of a nonwoven material. In this case, the first wheel blade 125 may roughly grind the back surface of the wafer 90, that is, rough grinding, and the second wheel blade 126 may finely back the back surface of the wafer 90. Polishing, that is, grinding polishing may be performed.

In another embodiment, the wheel blades can be constructed and arranged as shown in FIG. That is, the wheel blades include a circular ring-shaped first wheel blade 225 provided at the bottom edge of the wheel body 224, and a circular ring-shaped second wheel blade 226 disposed inside the first wheel blade 225. ) And a third wheel blade 227 having a circular ring shape disposed inside the second wheel blade 226. In this case, the first, second wheel, and third blades 225, 226, and 227 may be formed of diamond materials having particle sizes of different sizes, and may be arranged in a concentric shape. For example, the particle size of the first wheel blade 225 may have 2000 mesh, the particle size of the second wheel blade 226 may have 2500 mesh, and the particle size of the third wheel blade 227 is 3000 mesh. It may have a. In addition, the first wheel blade 225, the second wheel blade 226, and the third wheel blade 227 may be formed of different materials. For example, the first wheel blade 225 and the second wheel blade 226 may be formed of a diamond material having a different particle size or strength, and the third wheel blade 227 may be formed by compressing polyethylene fiber or the like with a polymer. It may be formed of a nonwoven material. In this case, the first wheel blade 225 and the second wheel blade 226 may roughly polish the back surface of the wafer 90, that is, rough polishing, and the third wheel blade 227 may be the wafer 90. The back side of the finely polished, that is, grinding polishing can be performed.

In another embodiment, the wheel blades may be constructed and arranged as shown in FIG. That is, the wheel blades have a circular ring-shaped first wheel blade 325 provided at the bottom edge of the wheel body 124, and a disk-shaped second wheel blade 329 disposed inside the first wheel blade 325. It can be configured as. In this case, the first wheel blade 325 and the second wheel blade 329 may be formed of different materials. For example, the first wheel blade 325 may be formed of a material obtained by sintering diamond fine particles and resin, that is, a diamond material, and a material obtained by compressing polyethylene fiber or the like of the second wheel blade 329 with a polymer, that is, a nonwoven fabric. It may be formed of a material. In this case, the first wheel blade 325 may roughly polish the back surface of the wafer 90, that is, rough polishing, and the second wheel blade 329 may finely polish the back surface of the wafer 90, Grinding polishing can be performed.

Meanwhile, the wheel moving units 130 and 230 serve to elevate at least one of the wheel blades of the polishing wheel 127 or the entire wheel blades, respectively, and may be implemented in various ways and in various configurations. For example, a ball screw type, a cylinder type, or a linear motor type may be applied to the wheel moving unit.

2 to 5, the wheel moving units 130 and 230 are provided at connection shafts 139 and 239 coupled to upper portions of the wheel blades 125 and 126, and at one end of the connection shafts 139 and 239, respectively. The bearings 137 and 237, the cams 138 and 238 which are in contact with the bearings 137 and 237 so as to move the connecting shafts 139 and 239, and are reciprocated for a predetermined distance in the vertical direction of the connecting shafts 139 and 239, and the rotating shafts 134 and 234 connected to the cams 138 and 238. ), The rotary motors 132 and 232 for rotating the rotary shafts 134 and 234 a predetermined distance while rotating the rotary shafts 134 and 234 so that the cams 138 and 238 are reciprocated, and the connecting shafts 139 and 239 moved by the cams 138 and 238. It may include an elastic member (131, 231) to return to the position of, and may be arranged in a plurality at a predetermined angle along the circumferential direction of the wheel clamp 121. In this case, through-holes 122 and 135 of a predetermined size may be formed in the wheel body 124 and the wheel clamp 123 to pass through the connecting shafts 139 and 239 coupled to the wheel blades 125 and 126, respectively. In addition, an installation space 133 having a predetermined size is formed in the upper portion of the connecting shafts 139 and 239, the upper portion of the through hole 135 formed in the wheel clamp 123, such that the cams 138 and 238 or the connecting shafts 134 and 234 are arranged. Can be.

In detail, the bearings 137 and 237 may be formed in a spherical shape. In this case, the upper ends of the connecting shafts 139 and 239 may be provided with recesses so that the bearings 137 and 237 having a spherical shape may be rolled only at the upper ends of the connecting shafts 139 and 239. In addition, the lower surfaces of the cams 138 and 238 may be formed as inclined surfaces so as to press the bearings 137 and 237 in contact with the lower portions when the cams 138 and 238 are moved in one direction by the rotation shafts 134 and 234. For example, the cams 138 and 238 may be formed in a trapezoidal shape. The rotating shafts 134 and 234 have a cylindrical shape having a predetermined length, and one end thereof is connected to the cams 138 and 238 as described above, and the other end thereof penetrates the rotary motors 132 and 232 or is fitted into the rotary motors 132 and 232. At this time, a spiral is formed on the outer circumferential surface of the rotary shafts 134 and 234, and the rotary motors 132 and 234 may include a rotor having a nut of a predetermined size so that the rotary shafts 134 and 234 are fitted. In this case, a separate spiral corresponding to the spiral of the rotation shafts 134 and 234 may be further formed on the inner circumferential surface of the nut provided in the rotor. Therefore, when the rotation motors 132 and 232 are rotated in the forward or reverse direction, the rotation shafts 134 and 234 are reciprocated in the forward or backward direction by these spirals.

In addition, the elastic members 131 and 231 serve to return the connecting shafts 139 and 239 moved by the cams 138 and 238 to their original positions, and the locking protrusions 140 and 240 protrude to the side surfaces of the connecting shafts 139 and 239. ) And the coil springs disposed between the support protrusions 128 and 228 protruding to a predetermined size from the wheel body 124 to be provided below the locking protrusions 140 and 240 so as to face the locking protrusions 140 and 240. Accordingly, the connecting shafts 139 and 239 that are pressed down by the cams 138 and 238 of the wheel moving units 130 and 230 by a predetermined distance are caused by the projections 128 and 140 as described above when the cams 138 and 238 do not press the connecting shafts 139 and 239. It is possible to return to the original position by the action of the supported elastic members (131, 231). In this case, the locking protrusions 140 and 240, the support protrusions 128 and 228, and the elastic members 131 and 231 may be installed in the through-holes 122 of the wheel body 124 formed such that the connecting shafts 139 and 239 penetrate.

In addition, the wheel moving units 130 and 230 may further include distance detectors 136 and 236 positioned on one side of the rotary motors 132 and 232 to sense the moving distances of the cams 138 and 238 moved by the rotation shafts 134 and 234. In this case, the descending distances of the wheel blades 125 and 126 are proportional to the moving distances of the cams 138 and 238, so that a central controller (not shown) which controls the wafer polishing apparatus 100 as a whole is transmitted from the distance sensors 136 and 236. By controlling the rotation of the rotary motors 132 and 232 according to the data, the moving distance of the cams 138 and 238 and the falling distance of the wheel blades 125 and 126 are controlled. In this case, the distance detectors 136 and 236 may be encoders that generate a predetermined signal as the cams 138 and 238 and the rotation shafts 134 and 234 connected to the cams 138 and 238 are moved a predetermined distance.

Meanwhile, the wheel moving units 130 ′ and 230 ′ may be configured in other embodiments as shown in FIGS. 8 and 9. That is, the wheel moving units 130 'and 230' are connected to the piston rods 139 'and 239' coupled to the upper portions of the wheel blades 125 and 126, and the piston rods 139 'and 239' are connected to the piston rods 139. It may include a cylinder (132 ', 232') for elevating the ', 239' a predetermined distance. In this case, the cylinder may be a hydraulic cylinder or an air cylinder.

Hereinafter, a method of polishing a wafer using the wafer polishing apparatus of the present invention configured as described above will be described in detail.

10 is a block diagram showing an embodiment of a wafer polishing method according to the present invention, Figure 11 is a block diagram showing another embodiment of a wafer polishing method according to the present invention, Figure 12 is a wafer according to the present invention A block diagram showing another embodiment of the polishing method.

First, referring to FIG. 7, an embodiment of a wafer polishing method using the wafer polishing apparatus of the present invention will be described in detail.

First, when the wafer 90 to be ground is transferred from the outside, a wafer transfer robot (not shown) or the like loads the wafer 90 thus transferred to the wafer chuck 150 (S11).

Thereafter, when the wafer 90 is loaded into the wafer chuck 150, the wafer chuck 150 fixes the loaded wafer 90 to the upper surface of the wafer chuck 150 by vacuum suction or the like.

Subsequently, when the wafer 90 is fixed, the polishing head 120 descends a predetermined distance from the top of the wafer chuck 150 to the bottom thereof, and then the wafer (primaryly using the plurality of wheel blades provided at the bottom thereof) 90) (Grinding) (S13). At this time, the wheel clamp 123 provided in the polishing head 120 and the polishing wheel 127 clamped thereto are rotated in one direction by the rotation of the head motor 121, and the wafer chuck 150 is the polishing wheel 127. It is rotated in the direction opposite to the direction of rotation of the other direction. In this case, the wheel blades may be formed of a diamond material having particle sizes of different sizes, respectively, and may be arranged in a concentric shape. For example, the grain size of one wheel blade may have 2000 mesh and the grain size of the other wheel blade may have 3000 mesh.

Subsequently, when the primary polishing is completed, the polishing head 120 ascends to the upper portion of the wafer chuck 150 by a predetermined height, and after raising, some of the plurality of wheel blades provided in the polishing head 120 are raised to a predetermined height. It is lowered to (S15). In this case, the lowered wheel blade may be a wheel blade having a particle size of the smallest size among the plurality of wheel blades.

Then, when some of the plurality of wheel blades are lowered to a predetermined height, the polishing head 120 is lowered back to the upper surface of the wafer chuck 150, and then using only some of the wheel blades lowered of the plurality of wheel blades 2 The wafer 90 is ground by grinding (S17).

Subsequently, when wafer polishing is completed due to the first polishing and the second polishing, the wafer transfer robot or the like unloads the wafer 90 seated on the wafer chuck 150 to the outside (S19) to complete the wafer polishing process. Done.

Next, another embodiment of the wafer polishing method using the wafer polishing apparatus of the present invention will be described in detail with reference to FIG. 8.

First, when the wafer 90 to be ground is transferred from the outside, the wafer transfer robot or the like loads the transferred wafer 90 into the wafer chuck 150 (S21).

Thereafter, when the wafer 90 is loaded into the wafer chuck 150, the wafer chuck 150 fixes the loaded wafer 90 to the upper surface of the wafer chuck 150 by vacuum suction or the like.

Subsequently, when the wafer 90 is fixed, the polishing head 120 lowers any part of the plurality of wheel blades provided below the predetermined height, and then the lowered wheel blade contacts the wafer 90. After descending a predetermined distance toward the wafer chuck 150, and after descending, the wafer is first ground by using some of the wheel blades dropped among the plurality of wheel blades (S23). In this case, any of the lowered wheel blades may be a diamond material having a particle size of 2000 mesh.

Subsequently, when the primary polishing is completed, the polishing head 120 ascends the upper portion of the wafer chuck 150 by a predetermined height, and after the polishing, the wheel of any of the plurality of wheel blades provided in the polishing head 120 is raised. The blade is raised and the other part is lowered to a predetermined height (S25).

Thereafter, when another part of the plurality of wheel blades is lowered to a predetermined height, the polishing head 120 descends back to the upper surface of the wafer chuck 150 and then uses only some of the other wheel blades lowered among the plurality of wheel blades. The wafer is second polished (Grinding) (S27). In this case, the other lowered wheel blade may be a diamond material having a particle size of 3000 mesh.

Subsequently, when wafer polishing is completed due to primary polishing and secondary polishing, the wafer transfer robot or the like unloads the wafer 90 seated on the wafer chuck 150 to the outside (S29) to complete the wafer polishing process. Done.

Next, another embodiment of the wafer polishing method using the wafer polishing apparatus of the present invention will be described in detail with reference to FIG. 9.

First, when the wafer 90 to be ground is transferred from the outside, the wafer transfer robot or the like loads the transferred wafer 90 into the wafer chuck 150 (S21).

Thereafter, when the wafer 90 is loaded into the wafer chuck 150, the wafer chuck 150 fixes the loaded wafer 90 to the upper surface of the wafer chuck 150 by vacuum suction or the like.

Subsequently, when the wafer 90 is fixed, the polishing head 120 lowers any part of the plurality of wheel blades provided below the predetermined height, and then the lowered wheel blade contacts the wafer 90. After descending a predetermined distance toward the wafer chuck 150, and after descending, the wafer 90 is first ground by using some of the wheel blades dropped among the plurality of wheel blades (S23). In this case, some of the lowered wheel blades may be made of diamond.

Subsequently, when the primary polishing is completed, the polishing head 120 ascends the upper portion of the wafer chuck 150 by a predetermined height, and after the polishing, the wheel of any of the plurality of wheel blades provided in the polishing head 120 is raised. The blade is raised and the other part is lowered to a predetermined height (S25).

Thereafter, when another part of the plurality of wheel blades is lowered to a predetermined height, the polishing head 120 descends back to the upper surface of the wafer chuck 150 and then uses only some of the other wheel blades lowered among the plurality of wheel blades. In the second step, the wafer 90 is finely polished (S28). In this case, the lowered portion of the wheel blade may be formed of a nonwoven material. In this case, some of the wheel blades that first polish the wafer may roughly polish, i.e., rough, the backside of the wafer, and some other wheel blades that secondly polish the wafer may finely polish the backside of the wafer. That is, grinding polishing can be performed.

Subsequently, when wafer polishing is completed due to primary grinding and secondary polishing, the wafer transfer robot and the like unload the wafer seated on the wafer chuck to the outside (S29) to complete the wafer polishing process. Done.

As mentioned above, although the present invention has been described with reference to the illustrated embodiments, it is only an example, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the scope of the present invention should be defined by the appended claims and their equivalents.

As described above, according to the wafer polishing apparatus of the present invention and the wafer polishing method using the same, the wafer is polished using a plurality of wheel blades having different particle sizes or the wafer is polished using a plurality of wheel blades of different materials. Therefore, it is possible to rapidly reduce the thickness of the chip while significantly improving the surface roughness of the chip to be polished.

In addition, according to the wafer polishing apparatus of the present invention and the wafer polishing method using the same, the first polishing is performed using a wheel blade formed of a diamond material or the like, and the second polishing is performed using a wheel blade formed of a nonwoven material or the like. Since the wafer can be polished quickly, the wafer can be micropolished. Therefore, by using the present invention, it is possible to drastically shorten the time due to wafer polishing, thereby maximizing the yield.

Claims (23)

Wheel body; A plurality of wheel blades provided on one side of the wheel body to polish the wafer; And, And a wheel moving unit for reciprocating at least one of the wheel blades. The method of claim 1, The wheel blades are provided below the wheel body, And the wheel moving unit lifts at least one of the wheel blades. The method of claim 1, And the wheel blades are formed of a diamond material. The method of claim 3, And the wheel blades have different particle sizes. The method of claim 1, The wheel blades are wafer polishing apparatus, characterized in that each formed in a circular ring shape having a different diameter. The method of claim 5, And the wheel blades are arranged concentrically. The method of claim 1, And the wheel blades comprise a first wheel blade formed of a diamond material and a second wheel blade formed of a nonwoven material. The method of claim 7, wherein The first wheel blade is formed in a circular ring shape, And the second wheel blade is disposed inside the first wheel blade. The method of claim 1, And the wheel blades include a first ring blade having a circular ring shape provided at an edge of the polishing wheel, and a second wheel blade disposed inside the first wheel blade. The method of claim 9, And the first wheel blade and the second wheel blade are formed of different materials. The method of claim 1, The wheel movement unit is connected to one side of the one of the wheel blades, the bearing is provided on one side end of the connection shaft, and the contact contact the bearing so that the connecting shaft is moved a predetermined distance in the vertical direction of the connecting shaft And a cam for reciprocating movement, a rotation shaft connected to the cam, and a rotation motor for reciprocating the rotation shaft by a predetermined distance while rotating the rotation shaft so that the cam is reciprocated. The method of claim 11, The wheel movement unit further comprises a distance sensor located on one side of the rotary motor to detect the moving distance of the cam. The method of claim 11, The wheel moving unit further comprises an elastic member for returning the connecting shaft moved by the cam to its original position. The method of claim 1, The wheel moving unit includes a piston rod coupled to one side of the one wheel blade, and a wafer polishing apparatus comprising a cylinder connected to the piston rod for reciprocating the piston rod a predetermined distance. Loading a wafer into a wafer chuck; A primary polishing step of polishing the wafer using a plurality of wheel blades; Lowering some of the wheel blades; And, And a secondary polishing step of polishing the wafer with the lowered wheel blades. The method of claim 15, The wheel blades are a wafer polishing method using a wafer polishing apparatus, characterized in that formed of a diamond material. The method of claim 16, The wheel blades are a wafer polishing method using a wafer polishing apparatus, characterized in that each having a different size of particle size. The method of claim 17, The secondary polishing step is a wafer polishing method using a wafer polishing apparatus, characterized in that for polishing the wafer with a wheel blade having the smallest particle size of the wheel blades. The method of claim 15, The wheel blades are a wafer polishing method using a wafer polishing apparatus, characterized in that including a wheel blade formed of a diamond material and a wheel blade formed of a nonwoven material. The method of claim 19, The second polishing step is a wafer polishing method using a wafer polishing apparatus, characterized in that for fine grinding the wafer with a wheel blade formed of a non-woven material. Loading a wafer into a wafer chuck; A primary polishing step of polishing the wafer using any one of a plurality of wheel blades; Lowering another of the wheel blades; And, And a secondary polishing step of polishing the wafer with the lowered wheel blades. The method of claim 21, The second polishing step is a wafer polishing method using a wafer polishing apparatus, characterized in that to finely polish the wafer with a wheel blade having a particle size smaller than the first polishing step. The method of claim 21, The first polishing step is to polish the wafer with a wheel blade formed of a diamond material, The second polishing step is a wafer polishing method using a wafer polishing apparatus, characterized in that for fine grinding the wafer with a wheel blade formed of a non-woven material.

Images