TWI863991B - Grinding device - Google Patents

Abstract

[Topic] Properly transporting a wafer including a curved modified layer. [Solution] When a wafer (W) on a temporary platform (61) is transported to a suction cup platform by a transport mechanism (31), the center of the wafer (W) is held by a suction pad (81), and the peripheral portion of the wafer (W) is held by a plurality of peripheral suction holding portions (89). Thus, sagging of the peripheral portion of the wafer (W) can be suppressed, and the wafer (W) can be firmly held. Therefore, even if the wafer (W) is bent, the wafer (W) on the temporary platform (61) can be well held and properly transported to the holding surface of the suction cup platform. Therefore, in order to properly transport the wafer (W), it is not necessary to perform processing on the wafer (W) to suppress bending. As a result, the processing time of the wafer (W) can be shortened.

Description

Grinding device

The present invention relates to a grinding device.

There is a processing method (SDBG) in which a modified layer is formed inside a wafer along a predetermined dividing line, the back side of the wafer is ground to be thinned, and the wafer is divided into individual components (see Patent Document 1).

In the processing method shown above, the modified layer is formed on the surface side of the wafer. Therefore, due to the formation of the modified layer, the inside of the wafer expands, and the wafer is sometimes bent and concave on the back side. At this time, it is difficult to transport the wafer to the suction table of the grinding device.

Therefore, there is a processing method for suppressing bending (warp) by forming a modified layer on the back side of the wafer (see Patent Document 2). In addition, there is also a technology for performing processing on the wafer to suppress bending (see Patent Document 3). [Prior Technical Document] [Patent Document]

[Patent Document 1] Japanese Patent Publication No. 2006-012902 [Patent Document 2] Japanese Patent Publication No. 2013-214601 [Patent Document 3] Japanese Patent Publication No. 2016-025188

(Invent the problem you want to solve)

However, changing the formation position of the metamorphic layer or performing processing on the wafer simply to suppress the bending of the wafer will lead to deterioration of production efficiency.

The purpose of the present invention is to properly transport a curved wafer including a modified layer. (Technical means for solving the problem)

The grinding device of the present invention (this grinding device) is a device that forms an element in an area demarcated by a predetermined dividing line on a surface, adheres an adhesive tape to the surface, forms a modified layer inside along the predetermined dividing line, and holds a wafer that is curved to have a concave back side by the holding surface of a suction cup platform through the adhesive tape, and grinds the back side of the wafer by a grinding stone. The grinding device at least comprises: a temporary platform for temporarily placing the wafer; a suction cup platform having a holding surface for holding the wafer through the adhesive tape; and a conveying means for conveying the wafer from the temporary platform to the suction cup platform, the conveying means comprising: a central suction holding portion for sucking and holding the central portion of the back side of the wafer; and a suction holding portion for sucking and holding the original wafer. The peripheral suction holding part holds the peripheral part of the wafer held by the central suction holding part; and the annular pressing part presses the peripheral part of the wafer whose central part contacts the holding surface against the holding surface. When the transporting means attracts and holds the wafer by the temporary platform, the central suction holding part and the peripheral suction holding part are connected to the suction source. When the transporting means transports the wafer to the holding surface of the suction pad platform, the central suction holding part and the peripheral suction holding part are connected to the air supply source to eliminate the suction holding force. The pressing part presses the peripheral part of the wafer against the holding surface, and the holding surface is connected to the suction source, so that the grinding stone grinds the wafer originally attracted and held on the holding surface. (Effect of the invention)

In the present grinding device, when the wafer on the temporary platform is transferred to the suction pad platform by the transfer means, the center of the wafer is held by the central suction holding part, and the peripheral part of the wafer is held by the peripheral suction holding part. In this way, the peripheral part of the wafer can be suppressed from sagging, and the wafer can be firmly held. Therefore, even if the wafer is bent, the wafer on the temporary platform can be well held and properly transferred to the holding surface of the suction pad platform. Therefore, in order to properly transfer the wafer, in the present grinding device, it is not necessary to actually perform processing on the wafer to suppress bending. As a result, the processing time of the wafer can be shortened.

The grinding apparatus 1 shown in FIG. 1 is configured to fully automatically perform a series of operations including loading, grinding, cleaning, and unloading on a wafer W.

The wafer W shown in FIG1 is, for example, a circular semiconductor wafer. As shown in FIG2, on the surface Wa of the wafer W, components D are formed in each of the portions divided by the grid-shaped predetermined dividing lines L. In addition, along the predetermined dividing lines L, a modified layer not shown is formed inside the wafer W. The surface Wa of the wafer W faces downward in FIG1 and is protected by a protective tape T. The back side Wb of the wafer W becomes the processed surface to which grinding is applied.

The grinding device 1 includes a substantially rectangular first device base 11 , a second device base 12 connected to the rear (+Y direction side) of the first device base 11 , a support column 13 extending upward, and a frame 14 covering the first device base 11 and the second device base 12 .

A first cassette stage 151 and a second cassette stage 152 are provided on the front side (-Y direction side) of the first device base 11. A first cassette 151a for accommodating wafers W before processing is placed on the first cassette stage 151. A second cassette 152a for accommodating wafers W after processing is placed on the second cassette stage 152.

The first cassette 151 a and the second cassette 152 a include a plurality of shelves therein, and wafers W are housed one by one in each shelf.

The opening (not shown) of the first cassette 151a faces the +Y direction side. A robot 155 is arranged on the +Y direction side of the opening. The robot 155 has a suction pad having a full suction surface for sucking and holding the back side Wb of the wafer W. The robot 155 moves the processed wafer W into the second cassette 152a. In addition, the robot 155 moves the unprocessed wafer W from the first cassette 151a and places it on the temporary platform 61.

The temporary platform 61 is used to temporarily place the wafer W, and is located adjacent to the robot 155. As shown in FIG1 and FIG3, the temporary platform 61 is provided with a plurality of alignment means 63. The alignment means 63 is a reduced diameter alignment pin, which moves along the radial direction of the temporary platform 61, thereby aligning (centering) the wafer W placed on the temporary platform 61 with the back side Wb formed upward at a predetermined position. Among them, in this embodiment, the wafer W is bent as shown in FIG3 so that the back side Wb is concave and the peripheral part is warped upward.

In addition, as shown in FIG3 , the temporary platform 61 has a temporary holding surface 62 that can adsorb and hold the protective tape T side of the wafer W. The temporary holding surface 62 can be connected to either the first air source 66 or the first suction source 67 through either the first air valve 64 or the first suction valve 65. When the alignment is performed by the alignment means 63 , as shown in FIG3 , both the first air valve 64 and the first suction valve 65 are closed.

As shown in FIG1 , a loading mechanism 31 is provided adjacent to the temporary stage 61 . The loading mechanism 31 is an example of a transporting means. The loading mechanism 31 sucks and holds the wafer W temporarily placed on the temporary stage 61 , transports it to the chuck stage 30 , and places it on the holding surface 300 .

The suction pad platform 30 has a holding surface 300 for sucking the wafer W. The holding surface 300 is connected to a suction source and sucks and holds the wafer W through a protective tape T. The suction pad platform 30 can rotate about a central axis extending in the Z-axis direction through the center of the holding surface 300 while holding the wafer W on the holding surface 300 .

The suction cup platform 30 is surrounded by a cover 39. The cover 39 is connected to a bellows cover 39a that is retractable in the Y-axis direction. Then, a Y-axis moving means (not shown) is provided below the cover 39 and the bellows cover 39a. The suction cup platform 30 can be reciprocated in the Y-axis direction by the Y-axis moving means.

A support column 13 is erected at the rear (+Y direction side) of the second device base 12. In front of the support column 13, a grinding device 7 for grinding the wafer W and a grinding feed device 2 for moving the grinding device 7 in the grinding feed direction, that is, the Z axis direction are provided.

The grinding feed means 2 includes: a pair of Z-axis guide rails 21 parallel to the Z-axis direction, a Z-axis moving stage 23 sliding on the Z-axis guide rails 21, a Z-axis ball screw 20 parallel to the Z-axis guide rails 21, a Z-axis servo motor 22, and a holder 24 mounted on the front face (surface) of the Z-axis moving stage 23. The holder 24 holds the grinding means 7.

The Z-axis moving platform 23 is provided to be slidable on the Z-axis guide rail 21. A nut portion (not shown) is fixed to the rear side (back side) of the Z-axis moving platform 23. The Z-axis ball screw 20 is screwed into the nut portion. The Z-axis servo motor 22 is connected to one end of the Z-axis ball screw 20.

In the grinding feed means 2, the Z-axis servo motor 22 rotates the Z-axis ball screw 20, thereby the Z-axis moving platform 23 moves in the Z-axis direction along the Z-axis guide rail 21. Thereby, the holder 24 mounted on the Z-axis moving platform 23 and the grinding means 7 held in the holder 24 also move in the Z-axis direction together with the Z-axis moving platform 23.

The grinding means 7 comprises: a spindle housing 71 fixed to the holder 24, a spindle 70 rotatably held in the spindle housing 71, a motor 72 for rotationally driving the spindle 70, a wheel seat 73 mounted on the lower end of the spindle 70, and a grinding wheel 74 supported on the wheel seat 73.

The spindle housing 71 is held by the holder 24 so as to extend in the Z-axis direction. The spindle 70 extends in the Z-axis direction so as to be orthogonal to the holding surface 300 of the suction cup stage 30 and is rotatably supported by the spindle housing 71.

The motor 72 is connected to the upper end side of the spindle 70. The spindle 70 is rotated around the rotation axis along the Z-axis direction by the motor 72. The wheel seat 73 is formed in a disc shape and is fixed to the lower end (front end) of the spindle 70. The wheel seat 73 supports the grinding wheel 74.

The grinding wheel 74 is formed to have substantially the same diameter as the wheel base 73. The grinding wheel 74 includes: a circular ring-shaped wheel base (ring-shaped base) 740 formed of a metal material such as stainless steel. A plurality of grinding stones 741 arranged in a ring shape are fixed to the lower surface of the wheel base 740 over the entire circumference. The grinding stones 741 grind the back surface Wb of the wafer W held on the suction pad stage 30.

A thickness measuring device 38 is provided adjacent to the chuck platform 30. The thickness measuring device 38 can measure the thickness of the wafer W in a contact manner during grinding, for example.

The ground wafer W is carried out by the carrying-out mechanism 36. The carrying-out mechanism 36 as the first carrying-out means has a suction pad having a full suction surface for sucking and holding the back side Wb of the wafer W. The carrying-out mechanism 36 sucks and holds the back side Wb of the ground wafer W placed on the suction pad platform 30 by the suction pad, and carries it out from the suction pad platform 30 and transports it to the spinner platform 27 of the single-wafer spinner cleaning unit 26.

The spinner cleaning unit 26 includes a spinner stage 27 for holding the wafer W, and various nozzles (not shown) for spraying cleaning water and dry air toward the spinner stage 27 .

In the spinner cleaning unit 26, the spinner stage 27 holding the wafer W is lowered into the first device base 11. Then, in the first device base 11, cleaning water is sprayed toward the back surface Wb of the wafer W, and the back surface Wb is cleaned by the spinner. After that, dry air is sprayed onto the wafer W, and the wafer W is dried.

The wafer W cleaned by the spinner cleaning unit 26 is carried into the second cassette 152a by the robot 155 serving as the second carrying-out means.

In addition, a touch panel 40 is provided on the side surface of the -Y side of the frame 14. The touch panel 40 displays various information such as the processing status of the grinding device 1 and the processing conditions related to the processing of the wafer W by the grinding device 1. In addition, the touch panel 40 is also used to input various information such as the processing conditions. As shown above, the touch panel 40 functions as an input means for inputting information, and also functions as a display means for displaying the input information.

In addition, the grinding device 1 has a control means 3 for controlling each component of the grinding device 1 inside the frame 14. The control means 3 controls each component of the grinding device 1 to perform the processing desired by the operator on the wafer W. In addition, the control means 3 controls the transfer processing of the wafer W to the holding surface 300 of the suction table 30 by the loading mechanism 31.

The following describes the loading mechanism 31 as a characteristic structure of the grinding device 1. As shown in FIG. 4 , the loading mechanism 31 includes: a suction pad 81 having a suction surface 82, a plurality of peripheral suction holding portions 89, a plate 83 supporting the suction pad 81 and the peripheral suction holding portions 89, a support portion 84 supporting the plate 83, an arm portion 85 having the support portion 84, and a lifting means 86 for lifting and lowering the arm portion 85.

In addition, the loading mechanism 31 includes a first annular pad 87 disposed in an annular shape with the center of the lower surface 83a as the center on the lower surface 83a of the plate 83, and a second annular pad 88 disposed in an annular shape concentric with the first annular pad 87 on the outer side of the first annular pad 87 in the lower surface 83a of the plate 83. The first annular pad 87 is an example of an annular pressing portion, and presses the outer peripheral portion of the wafer W to the holding surface 300 by making the central portion contact the holding surface 300.

The suction surface 82 of the suction pad 81 is used to suction and hold the central portion of the back surface Wb of the wafer W. The suction pad 81 is provided at the lower end of the shaft 80. The suction pad 81 is an example of a central suction and holding portion.

The shaft 80 passes through the center of the plate 83 so as to be able to rise and fall freely in a direction perpendicular to the suction surface 82 of the suction pad 81. Therefore, the plate 83 supports the suction pad 81 so as to be able to rise and fall freely in a direction perpendicular to the suction surface 82 of the suction pad 81 through the shaft 80.

In addition, the shaft 80 is located above the plate 83 and penetrates the arm 85 in a direction perpendicular to the suction surface 82 so as to be freely raised and lowered.

An upper end plate 93 having an outer diameter larger than that of the shaft 80 is provided at the upper end of the shaft 80 passing through the arm portion 85. The upper end plate 93 prevents the shaft 80 from falling downward from the arm portion 85.

In addition, a fixing plate 94 having an outer diameter thicker than the shaft 80 is provided at the approximate center of the shaft 80. The fixing plate 94 is penetrated by the shaft 80 between the lower surface 85a of the arm 85 and the upper surface 83b of the plate 83. In addition, a coil spring 95 is provided between the upper surface of the fixing plate 94 and the lower surface 85a of the arm 85. The coil spring 95 can be extended and retracted in the direction in which the shaft 80 extends, that is, in a direction perpendicular to the suction surface 82 of the suction pad 81.

A through passage 80a is provided at the center of the shaft 80 to connect the upper end of the shaft 80 to the suction pad 81. The through passage 80a can be connected to the second air source (air supply source) 91 and the second suction source 92 through the opening 93a of the upper end plate 93 and to the second air valve 191 and the second suction valve 192.

The plate 83 of the support shaft 80 is provided on its lower surface 83a with: a plurality of peripheral suction and holding portions 89, a first annular pad 87 in an annular shape, and a second annular pad 88 in an annular shape arranged concentrically with the first annular pad 87.

The peripheral suction holding portion 89 is provided at a plurality of positions on the lower surface 83a of the plate 83 so as to be able to contact the peripheral portion of the wafer W held on the suction pad 81. In the present embodiment, as shown in FIG. 4 , the peripheral suction holding portion 89 is disposed between the first annular pad 87 and the second annular pad 88.

Each peripheral suction holding portion 89 has a peripheral suction pad 89a at the front end, and can be connected to any one of the third air source (air supply source) 101 and the third suction source 102 through any one of the third air valve 111 and the third suction valve 112. Each peripheral suction holding portion 89 is connected to the third suction source 102, and can use the peripheral suction pad 89a to suck and hold the peripheral portion of the back surface Wb of the wafer W that is originally sucked and held on the suction surface 82 of the suction pad 81.

In addition, the peripheral suction holding portion 89 is configured so that when a force is applied from below, the length of the portion protruding from the lower surface 83a of the plate 83 is changed. That is, the peripheral suction pad 89a can be brought close to the lower surface 83a of the plate 83. In addition, the peripheral suction holding portion 89 can be provided on the plate 83 in such a manner that the upper portion can enter the inside of the plate 83.

Furthermore, a plate connecting passage 96 is provided inside the plate 83. The plate connecting passage 96 connects between the first annular gasket 87 and the second annular gasket 88 on the lower surface 83a of the plate 83 and the upper surface 83b of the plate 83.

Between the first annular gasket 87 and the second annular gasket 88 in the lower surface 83a of the plate 83, there is provided a lower surface opening portion 96a which is an opening on the lower surface 83a side of the plate connecting passage 96.

Furthermore, an upper surface opening portion 96 b which is an opening on the upper surface 83 b side of the plate communication passage 96 is provided on the upper surface 83 b of the plate 83 .

The arm 85 has a support portion 84 on its lower surface 85a for supporting the plate 83. The support portion 84 has an on-off valve 97 at its lower end having a larger diameter than the support portion 84. The on-off valve 97 is accommodated in a space 96c where the plate connecting passage 96 of the plate 83 is expanded and can move in the vertical direction.

The on-off valve 97 can be moved in the up-down direction within a predetermined range, and on the other hand, is installed so as not to fall off from the plate connecting passage 96. The support portion 84 can support the plate 83 by the on-off valve 97.

In addition, when the opening and closing valve 97 moves downwardly toward the plate 83, it abuts against the bottom of the space 96c, closing (blocking) the plate connecting passage 96. On the other hand, when the opening and closing valve 97 moves upwardly toward the plate 83, it abuts against the upper portion of the space 96c, opening the plate connecting passage 96.

The arm 85 having the support portion 84 with the on-off valve 97 as shown above can move the plate 83 in the horizontal direction (in the direction parallel to the suction surface 82 of the suction pad 81). In addition, the arm 85 can be moved in the up-down direction together with the plate 83 by the lifting means 86. That is, the lifting means 86 can move the arm 85 together with the plate 83 in the direction perpendicular to the suction surface 82 of the suction pad 81.

The loading mechanism 31 having the structure shown above attracts and holds the wafer W temporarily placed on the temporary platform 61 as described above, and places it on the holding surface 300 of the suction cup platform 30. The operation of the loading mechanism 31 shown above is controlled by the control means 3 shown in FIG. 1

The following describes the operation of the loading mechanism 31 controlled by the control means 3.

As shown in FIG4 , the control means 3 (refer to FIG1 ) controls the arm 85 and the lifting means 86 to place the plate 83 above the temporary platform 61. Then, the control means 3 causes the alignment means 63 to retreat radially outward. In addition, the control means 3 controls the lifting means 86 to lower the plate 83, so that the suction surface 82 of the suction pad 81 supported at the lower end of the shaft 80 of the plate 83 abuts against the center of the wafer W.

In addition, the control means 3 closes the second air valve 191 and opens the second suction valve 192, thereby connecting the suction surface 82 of the suction pad 81 to the second suction source 92. As shown in FIG. 4 , the wafer W is held by the suction pad 81 of the carrying mechanism 31 by suction.

Next, the control means 3 (see FIG. 1 ) controls the lifting means 86 as shown in FIG. 5 , and together with the arm 85 , the plate 83 is lowered toward the temporary holding surface 62 of the temporary platform 61 and pressed. In addition, the control means 3 closes the third air valve 111 , and on the other hand, opens the third suction valve 112 , and connects the peripheral suction holding part 89 with the third suction source 102 . Thereby, the peripheral suction holding part 89 sucks and holds the peripheral part of the back side Wb of the wafer W .

As shown above, the control means 3 connects the suction pad 81 and the peripheral suction holding part 89 to the second suction source 92 and the third suction source 102 respectively, and uses the suction pad 81 and the peripheral suction holding part 89 to suck and hold the central part and the peripheral part of the wafer W on the temporary platform 61.

Afterwards, the control means 3 (see FIG. 1 ) controls the lifting means 86 to raise the plate 83 together with the arm 85 . As a result, as shown in FIG. 6 , the wafer W moves away from the temporary platform 61 .

In this state, the control means 3 controls the arm 85 and the lifting means 86 to place the plate 83 above the holding surface 300 of the suction cup platform 30. Then, the control means 3 (see FIG. 1 ) controls the lifting means 86 to lower the plate 83 from above the holding surface 300 together with the arm 85 as shown in FIG. 7 . In this way, the control means 3 makes the central part of the wafer W contact the holding surface 300.

In addition, the control means 3 (refer to FIG. 1 ) closes the second suction valve 192 and opens the second air valve 191 as shown in FIG. 8 . In addition, the control means 3 closes the third suction valve 112 and opens the third air valve 111 . Thereby, the suction pad 81 is connected to the second air source 91 , and the peripheral suction holding part 89 is connected to the third air source 101 . As a result, the suction pad 81 and the peripheral suction holding part 89 lose the suction holding force.

Next, the control means 3 controls the lifting means 86, together with the arm 85, to lower the plate 83 toward the holding surface 300 and press it.

As a result, as shown in FIG8 , the coil spring 95 disposed between the upper surface of the fixing plate 94 and the lower surface 85a of the arm 85 is contracted.

Next, the peripheral suction holding portion 89 and the first annular pad 87 provided on the lower surface 83a of the plate 83 contact the outer peripheral portion of the back surface Wb of the wafer W, and the second annular pad 88 contacts the outer side of the wafer W in the holding surface 300.

As shown above, the control means 3 forms an annular space S by a portion 300a outside the wafer W in the holding surface 300, an outer wall of the first annular pad 87, a lower surface 83a of the plate 83, and an inner wall of the second annular pad 88, as shown in FIG. 8 .

In addition, at this time, the on-off valve 97 provided at the front end of the support portion 84 of the arm portion 85 abuts against the bottom of the space 96c in the plate connecting passage 96 of the plate 83, and closes (blocks) the plate connecting passage 96. Thus, the annular space S forms a sealed chamber.

In addition, as shown in FIG8 , the holding surface 300 is connected to the fourth suction source 301 through the suction passage 303 and the fourth suction valve 302.

Next, the control means 3 opens the fourth suction valve 302 when the annular space S becomes a sealed chamber, thereby connecting the holding surface 300 with the fourth suction source 301. As described above, a portion of the holding surface 300 (the portion 300a that is further outward than the wafer W) forms a portion of the annular space S. Therefore, by connecting the holding surface 300 with the fourth suction source 301, the suction force of the holding surface 300 acts on the annular space S, and the annular space S of the sealed chamber becomes negative pressure.

As a result, the plate 83 is pressed toward the holding surface 300 by atmospheric pressure. Therefore, the outer peripheral portion of the wafer W is pressed against the holding surface 300 by the first annular pad 87 of the plate 83. As a result, the wafer W is adsorbed and held on the holding surface 300.

In addition, at this time, the peripheral suction holding portion 89 is pushed from below to the wafer W, and the peripheral suction pad 89a approaches the lower surface 83a of the plate 83.

After the wafer W is attracted and held on the holding surface 300, the control means 3 closes the second air valve 191 and the third air valve 111. In addition, the control means 3 controls the lifting means 86 to raise the arm 85. Thereby, the opening and closing valve 97 provided at the front end of the support portion 84 of the arm 85 abuts against the upper part of the space 96c in the plate connecting passage 96 of the plate 83, and the plate connecting passage 96 is opened. Thereby, the sealed chamber of the annular space S is destroyed, and the annular space S is opened to the atmosphere.

Among them, with regard to the structure in which the opening and closing valve 97 moves in the upward direction in the space 96c to open the plate connecting path 96, as shown in Figures 8, 9, and Figure 10 which enlarges the vicinity of the opening and closing valve 97, there is a plate connecting path 97a that connects the space 96c with the upper surface 83b of the plate 83 when the opening and closing valve 97 is far away from the bottom of the space 96c. Alternatively, as shown in FIG. 11, FIG. 12, and FIG. 13 which enlarges the vicinity of the open/close valve 97, when the open/close valve 97 is away from the bottom of the space 96c and the open/close valve 97 contacts the upper part of the space 96c, the plate connecting passage 96 is opened, and a valve connecting passage 97b is provided inside the open/close valve 97 and connects the upper and lower surfaces of the open/close valve 97.

Afterwards, the control means 3 (see FIG. 1 ) controls the lifting means 86 to further raise the arm 85. As a result, as shown in FIG. 9 , the coil spring 95 disposed between the upper surface of the fixing plate 94 and the lower surface 85a of the arm 85 is extended.

Then, the suction surface 82 of the suction pad 81, the outer peripheral suction holding portion 89 provided on the lower surface 83a of the plate 83, and the first annular pad 87 are separated from the back surface Wb of the wafer W. In addition, the second annular pad 88 is separated from the holding surface 300.

Afterwards, the wafer W held by suction on the holding surface 300 of the suction pad platform 30 is ground by the grinding stone 741 of the grinding means 7.

As shown above, in the grinding device 1 (refer to FIG. 1 ), when the wafer W on the temporary platform 61 is transported to the suction pad platform 30 by the loading mechanism 31, the center of the wafer W is held by the suction pad 81, and the outer peripheral portion of the wafer W is held by the plurality of outer peripheral suction holding parts 89. Thus, the sagging of the outer peripheral portion of the wafer W can be suppressed, and the wafer W can be firmly held.

Therefore, even if the wafer W is bent, the wafer W on the temporary platform 61 can be well held and properly transported to the holding surface 300 of the suction pad platform 30. Therefore, in the grinding device 1, since the wafer W is properly transported, it is not necessary to perform processing on the wafer W to suppress bending. As a result, the processing time of the wafer W can be shortened.

In addition, in the grinding device 1, the control means 3 forms a closed annular space S by using a portion 300a of the holding surface 300 that is outside the wafer W, the outer wall of the first annular pad 87, the lower surface 83a of the plate 83, and the inner wall of the second annular pad 88. In addition, the control means 3 forms the annular space S into a negative pressure by using the suction force of the holding surface 300, presses the plate 83 toward the holding surface 300 by atmospheric pressure, and presses the outer peripheral portion of the wafer W against the holding surface 300 by the first annular pad 87.

As shown above, in the grinding device 1, the outer peripheral portion of the wafer W is pressed against the holding surface 300 by using the suction force of the holding surface 300 and the atmospheric pressure. In this way, the pressing force of the wafer W against the holding surface 300 can be easily increased at low cost while suppressing the size and weight of the device.

In addition, in the grinding device 1, since the suction force of the holding surface 300 and the atmospheric pressure are utilized, even when the inclination of the holding surface 300 is changed in cooperation with the grinding means 7 (see FIG. 1 ), the wafer W can be pushed along the holding surface 300. Therefore, the wafer W can be easily attracted and held by the holding surface 300.

Among them, in this embodiment, the robot 155 moves the wafer W cleaned by the rotator cleaning unit 26 into the second cassette 152a. The robot 155 can also be configured to move the wafer W cleaned by the rotator cleaning unit 26 to a tape mounter (not shown) disposed horizontally in the grinding device 1 to replace it.

In addition, in the present embodiment, the plate 83 has a second annular pad 88 on its lower surface 83a in a concentric circle with the first annular pad 87. Alternatively, the plate 83 may not have the second annular pad 88. In this case, the first annular pad 87 does not use atmospheric pressure, but presses the outer peripheral portion of the wafer W against the holding surface 300 by the force transmitted from the arm 85 and the lifting means 86. Therefore, it is preferable to form the arm 85 that transmits the force of the lifting means 86 to have high rigidity.

1: Grinding device

2: Grinding feeding method

3: Control measures

7: Grinding methods

11: 1st device base

12: Second device base

13: Pillar

14: Frame

20: Z-axis ball screw

21: Z-axis guide rail 22: Z-axis servo motor 23: Z-axis moving platform 24: Holder 26: Rotator cleaning unit 27: Rotator platform 30: Suction cup platform 31: Loading mechanism 36: Unloading mechanism 38: Thickness gauge 39: Cover 39a: Bellows cover 40: Touch panel 61: Temporary platform 62: Temporary holding surface 63: Alignment means 64: First air valve 65: First suction valve 66: First air source 67: First suction Source 70: spindle 71: spindle housing 72: motor 73: wheel seat 74: grinding wheel 80: shaft 80a: through-path 81: suction pad 82: suction surface 83: plate 83a: lower surface 83b: upper surface 84: support part 85: arm part 85a: lower surface 86: lifting means 87: first annular pad 88: second annular pad 89: peripheral suction holding part 89a: peripheral suction pad 91: second air source (air supply source ) 92: Second suction source 93: Upper end plate 93a: Opening 94: Fixed plate 95: Coil spring 96: Connection path 96a: Lower surface opening 96b: Upper surface opening 96c: Space 97: On-off valve 97a: Plate connection path 97b: Valve connection path 101: Third air source (air supply source) 102: Third suction source 111: Third air valve 112: Third suction valve 151: First cassette carrier 152: Second cassette carrier 151a: 1st cassette 152a: 2nd cassette 155: robot 191: 2nd air valve 192: 2nd suction valve 300: holding surface 300a: part outside the wafer W 301: 4th suction source 302: 4th suction valve 303: suction path 740: wheel base (ring base) 741: grinding stone D: component L: splitting predetermined line S: ring space T: protective tape W: wafer Wa: surface Wb: back

[FIG. 1] is an oblique view showing the structure of the grinding device. [FIG. 2] is an oblique view showing the structure of the wafer. [FIG. 3] is an explanatory view showing the structure of the temporary platform. [FIG. 4] is an explanatory view showing the structure of the loading mechanism. [FIG. 5] is an explanatory view showing the state of the wafer being held by the suction pad and the peripheral suction holding portion. [FIG. 6] is an explanatory view showing the state of the wafer being separated from the temporary platform. [FIG. 7] is an explanatory view showing the state of the wafer being placed on the holding surface of the suction pad platform. [FIG. 8] is an explanatory view showing the state of the wafer being held by suction by the holding surface. [FIG. 9] is an explanatory view showing the state of the arm being raised and the plate being separated from the suction pad platform after the wafer is held by suction by the holding surface. [Fig. 10] is an explanatory diagram showing an enlarged view of the vicinity of the on-off valve. [Fig. 11] is an explanatory diagram showing other structures for opening and closing the plate connecting passage by the on-off valve. [Fig. 12] is an explanatory diagram showing other structures for opening and closing the plate connecting passage by the on-off valve. [Fig. 13] is an explanatory diagram showing an enlarged view of the vicinity of the on-off valve.

31: Move into the institution

61: Temporary platform

62: Temporarily hold the surface

63: Countermeasures

81: Attraction pad

82: Attraction surface

83: Board

84: Support Department

85: Arms

86: Lifting means

89: Peripheral suction and holding part

91: Second air source (air supply source)

92: Second source of attraction

93: Upper end plate

96: Liantong Road

97: Open/Close Valve

101: Third air source (air supply source)

102: The third source of attraction

111: Air valve No. 3

112: No. 3 suction valve

191: Second air valve

192: Second suction valve

T: Protective tape

W: Wafer

Wb:Back

Claims (1)

A grinding device forms an element in an area demarcated by a predetermined dividing line on a surface, a tape is attached to the surface, a modified layer is formed inside along the predetermined dividing line, and a wafer that is curved to have a concave back side is held by a holding surface of a suction cup platform through the tape, and the back side of the wafer is ground by a grinding stone. The grinding device at least comprises: a temporary platform for temporarily placing the wafer; a suction cup platform having a holding surface for holding the wafer through the tape; and a conveying means for conveying the wafer from the temporary platform to the suction cup platform, wherein the conveying means comprises: a central suction holding portion for sucking and holding the central part of the back side of the wafer; and a suction holding portion for sucking and holding the wafer originally sucked and held. The peripheral suction holding part of the wafer of the central suction holding part; and the annular pressing part that presses the peripheral part of the wafer whose central part contacts the holding surface against the holding surface, when the transporting means attracts and holds the wafer by the temporary platform, the central suction holding part and the peripheral suction holding part are connected to the suction source, when the transporting means transports the wafer to the holding surface of the suction pad platform, the central suction holding part and the peripheral suction holding part are connected to the air supply source to eliminate the suction holding force, the pressing part presses the peripheral part of the wafer against the holding surface, and the holding surface is connected to the suction source, and the grinding stone grinds the wafer that was originally attracted and held on the holding surface.

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