KR20140038304A - Machining method - Google Patents

Abstract

The present invention is to provide a process method capable of completely preventing fracture debris of an adhesive sheet from being attached to the side of a plate-shaped material when the plate-shaped material such as a wafer in which the adhesive sheet is attached to the other side is expanded and separated. A wafer (1) in which a protective member (11) is arranged on the surface (1a) and divided into an individual chip (3) along a prescribed division line is arranged in an expanding tape (13) as an adhesive sheet (12) is interposed and an excess part (12a) of the adhesive sheet (12) extruding from the outer side of the wafer (1) is divided (a first expansion step). The protective member (11) is continuously removed (a protective member removal step) and the chip (3) having a plurality of adhesive sheets (12) is obtained by expanding the expanding tape (13) greatly and dividing the adhesive sheets (12) along the chip (3) (a second expansion step). The fracture debris (12b) is prevented from being attached to the side (1a) of the wafer (1) by attaching the fracture debris (12b) of the adhesive sheet (12) generated when the adhesive sheet (12) is separated.

Description

Processing method {MACHINING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method for dividing a thin plate-like article, such as a semiconductor wafer, into a plurality of chips, and more particularly, to a method for processing a plate-shaped article having an adhesive sheet attached thereto.

Disc shaped wafers, such as a semiconductor wafer in which many devices were formed in the surface, are divided along the dividing line between devices, and are divided into semiconductor chips. By the way, in order to form the adhesive layer at the time of mounting a chip in advance, an adhesive sheet for forming an adhesive layer, such as DAF (Die Attach Film), is adhered to the back side of the wafer divided into individual chips, and then the adhesive sheet is divided. Technology is being provided. In that case, the adhesive sheet is formed slightly larger in diameter than the wafer, and a part of the adhesive sheet adhered to the back surface of the wafer protrudes from the outer circumference of the wafer.

As a method of dividing the adhesive sheet, a method of dividing the adhesive sheet by adhering an expanding tape or the like to the adhesive sheet side of the wafer divided into individual chips and having the adhesive sheet adhered to the back surface thereof, and expanding the expanding tape, The adhesive sheet of the part which protruded from the outer periphery of the wafer is also segmented, and there existed a problem that the shatter | damage of the adhesive sheet which arose at that time adheres to the surface of a wafer.

Therefore, in order to solve this problem, the technique which blows air with respect to the wafer surface by an air blow means during expansion of an expanding tape, and the technique which prevents the chipping of the adhesive sheet from sticking to the wafer surface is proposed (patent document 1). ).

Japanese Patent Publication No. 2009-272503

However, even with the technique described in the above document, it was difficult to completely prevent the breakage of the adhesive sheet from adhering to the wafer surface.

This invention is made | formed in view of the said situation, The main technical subject is that when the plate-shaped object, such as a wafer which adhered the adhesive sheet to the back surface, is divided and extended, it is completely adhered that the chip | wreck of the adhesive sheet adheres to the surface of a plate-shaped object. It is to provide a processing method that can be prevented.

The processing method of this invention is a processing method of the plate-shaped object which the protection member is arrange | positioned at the surface, and is divided into individual chips along a dividing line, and spreads a plate-shaped object on an expanding tape via the adhesive sheet of larger diameter than a plate-shaped object. A first expansion step of dividing the adhesive sheet protruding at least on the outer circumferential side of the plate-shaped article by expanding the expanding tape with the protective member disposed on the surface of the plate-shaped article after performing the adhesion step and the adhesion step. And a protective member removing step of removing the protective member disposed on the surface of the plate-shaped product after the first expansion step, and after the protective member removing step, expanding the expanding tape to correspond to the plate-shaped material. And a second expansion step of breaking the adhesive sheet along a plurality of the chips.

In the processing method of this invention, a 1st expansion step is performed in the state which arrange | positioned the protective member on the surface of a plate-shaped object, and the adhesive sheet which protruded to the outer peripheral side at least at this time is broken. The breaking chip | wreck of the adhesive sheet which arose at the time of a break is adhered on a protective member. After carrying out the first expansion step, since the protective member with broken debris is removed on the plate, it is possible to completely prevent the broken debris from adhering to the surface of the plate.

In the present invention, after performing the second expansion step, the annular frame is adhered to the expanding tape while the plate-shaped object is maintained with the gap between the individual chips formed by dividing, and the plate-shaped object is formed in the opening of the annular frame. It includes a form comprising an annular frame sticking step to form a plurality of the divided chip formed. According to this aspect, the space | interval between the individual chips after division | segmentation is maintained, and conveyance etc. can be performed, without damaging a chip | tip by handling an annular frame.

According to this invention, when extending and dividing plate-shaped objects, such as a wafer which adhere | attached the adhesive sheet on the back surface, the processing method which can completely prevent a chip | wreck of the adhesive sheet adheres to the surface of a plate-shaped object is provided.

1 is a perspective view illustrating a half cut step of a machining method according to an embodiment of the present invention.
2 is a perspective view illustrating a protective member adhesion step of a processing method according to one embodiment.
3 is a perspective view illustrating the back grinding step of the machining method of the embodiment;
4 is a perspective view showing an adhesion step of a processing method of one embodiment;
5 is a perspective view showing a first expansion step of the machining method of the embodiment;
6 is a cross-sectional view showing a first expansion step.
7 is a perspective view showing a state after the first expansion step.
8 is a perspective view illustrating a protective member removing step of the machining method of the embodiment;
9 is a perspective view illustrating a second expansion step of the machining method of the embodiment;
10 is a cross-sectional view illustrating a second expansion step.
11 is a cross-sectional view showing (a) the annular frame sticking step of the processing method of one embodiment, and (b) the cross-sectional view showing the expanding tape cut after the annular frame sticking step.
It is a perspective view which shows the state which carried out the wafer from the expanding apparatus after cutting an expanding tape.
FIG. 13 is a cross-sectional view showing an expansion device according to another embodiment, showing (a) a state in which a wafer is set, (b) a first expansion step is performed, and (c) a second expansion step is performed.

EMBODIMENT OF THE INVENTION Hereinafter, the processing method of the wafer which concerns on one Embodiment containing the processing method of this invention is demonstrated with reference to drawings.

(1) half cut step

Reference numeral 1 in FIG. 1 denotes a disk-shaped wafer (plate-shaped article) 1 such as a semiconductor wafer. On the surface 1a of the wafer 1, a plurality of scheduled dividing lines are set in a lattice shape, and a device 2 having an electronic circuit such as LSI in each of a plurality of rectangular shaped device regions divided by dividing scheduled lines. Are formed respectively. In the half cut step, grooves 1d having a depth from the surface 1a side of the wafer 1 to the finished thickness after grinding are formed along the division scheduled line.

As shown in FIG. 1, the wafer 1 adheres on the dicing tape 16 to which the annular dicing frame 15 adhered to the outer periphery, and the wafer 1 and the rotatable holding means not shown are shown in FIG. The dicing frame 15 is held. And the groove 1d is formed in the surface 1a of the wafer 1 with the cutting blade 71 of the cutting means 70 arrange | positioned above the wafer 1.

The cutting means 70 has a configuration in which a cutting blade 71 is attached to a tip of a spindle (not shown) accommodated in the spindle housing 72. The cutting blade 71 has a thickness of, for example, about 50 μm. do. In order to form the groove 1d in the wafer 1, the dividing scheduled line to be cut by the indexing transfer which rotates the holding means to make the dividing scheduled line parallel to the cutting direction (X direction) and moves in the Y direction. It selects and cuts the cutting blade 71 between division division lines, and the holding means is processed and conveyed to a X direction. If the grooves 1d are formed in all the division scheduled lines extending in one direction, the holding means is rotated by 90 ° so that the division scheduled lines on the other side are parallel to the X direction, and all the same extending in the other direction. A groove 1d is formed in the division scheduled line.

(2) protection member adhesion step

Next, as shown in FIG. 2, the protective member 11 is stuck to the whole surface 1a of the wafer 1 in which the groove 1d along the dividing scheduled line was formed. The protective member 11 is formed by, for example, a pressure-sensitive adhesive layer formed on one surface of a flexible resin sheet, and adheres to the surface 1a of the wafer 1 via the pressure-sensitive adhesive layer. As the protection member 11, the form which adhere | attaches a wafer with an adhesive agent etc. using hard plates, such as a silicon wafer, a glass substrate, and a ceramic substrate, may be sufficient.

(3) backside grinding step

Next, as shown in FIG. 3, the wafer 1 is held on the holding table 21 in accordance with the holding member 21 side, and the rear surface 1b of the wafer 1 exposed upward. ) Is ground by the grinding means 22 to thin the wafer 1 to a finished thickness (for example, about 50 µm to 100 µm).

The holding table 21 is a general well-known negative pressure chuck table which adsorbs and holds a workpiece by a negative pressure action by air suction on a circular horizontal holding surface formed of a porous material, and by a rotation driving mechanism (not shown). It will rotate around the axis. The grinding means 22 extends in the vertical direction, and the grinding wheel 25 is fixed to the front end of the spindle 23 which is rotationally driven by a motor (not shown). It is arrange | positioned so that it can move up and down above. On the outer periphery of the lower surface of the grinding wheel 25, a plurality of grindstones 26 are arranged in an annular shape and fixed. The grindstone 26 according to the material of the wafer 1 is used, for example, a diamond grindstone formed by hardening diamond abrasive grains with a binder such as a metal bond or a resin bond.

In the back grinding step, the wafer 1 is placed on the holding table 21 with the protective member 11 side aligned with the holding surface, and the wafer 1 is sucked and held by a negative pressure chuck. Then, the grinding means 22 is lowered in a state in which the holding table 21 is rotated in one direction at a predetermined speed, and the grinding wheel 26 of the rotating grinding wheel 25 is placed on the back surface 1b of the wafer 1. It presses and grinds the whole back surface 1b.

Since the wafer 1 is formed with a groove 1d having a depth reaching the finished thickness in the half cut step along the dividing line, the grindstone 26 is grooved 1d by grinding the back surface 1b to the finished thickness. And, as a result, the wafer 1 is divided into a plurality of chips 3 having a device 2 on the surface.

(4) adhesion step

Next, as shown in FIG. 4, the wafer 1 is placed on the back surface 1b of the wafer 1, which is divided into a plurality of chips 3 and the protective member 11 is adhered to the surface 1a. It arrange | positions on the expanding tape 13 through the adhesive sheet 12 of larger diameter. The expanding tape 13 is formed with a pressure-sensitive adhesive layer on one side of, for example, a synthetic resin sheet having elasticity such as polyvinyl chloride or polyolefin. In this case, the expanded tape 13 is wound in a rectangular shape or a roll shape larger than the wafer 1. Is used.

In the adhesion step, the adhesive sheet 12 made of DAF or the like is arranged in a circular shape on the adhesive layer side of the expanding tape 13, and then on the adhesive sheet 12, the back surface 1b of the wafer 1 is formed. ) Stick to the side. In addition, you may stick the wafer 1 to the expanding tape 13 in which the circular adhesive sheet 12 is arrange | positioned previously. Alternatively, the adhesive sheet 12 may be adhered to the back surface 1b of the wafer 1, and the adhesive sheet 12 may be adhered to the adhesive layer of the expanding tape 13. The adhesive sheet 12 is formed in a circular shape with a larger diameter than the wafer 1, and the excess portion 12a of the adhesive sheet 12 is exposed on the outer circumferential side of the wafer 1.

(5) first expansion step

Next, the expanding tape 13 is expanded to segment the excess portion 12a of the adhesive sheet 12 protruding toward the outer circumferential side of the wafer 1.

In the first expansion step, the expanding device 40 shown in Figs. 5 and 6 is used. The expanding device 40 has a clamp member 41 which grips four edges of the four sides of the expanding tape 13 and extends outwardly perpendicular to the edges. The clamp member 41 is the structure which combined the cross-sectional L-shaped frame 42 in the state of vertical symmetry, and the several roller 43 is arrange | positioned adjacent to each inside of each frame 42. As shown in FIG. These rollers 43 are supported by the frame 42 so as to be rotatable about a rotation axis orthogonal to the longitudinal direction of the frame 42. The expanding tape 13 is sandwiched between the upper and lower rollers 43, and when the expanding tape 13 is stretched in the direction along the short edge in the sandwiched state, the roller 43 rotates following it.

The expansion of the expanding tape 13 first passes four edges of the expanding tape 13 between the upper and lower frames 42 of the clamp members 41 of the expanding device 40, and the upper and lower frames. (42) is mutually close, and the expanding tape 13 is clamped by the roller 43 of the upper and lower sides. Subsequently, the clamping member 41 is moved outwardly (in the direction of the arrow in FIGS. 5 and 6) to expand the expanding tape 13. Since the roller 43 of the clamp member 41 is sandwiched, even if a strain biased by expansion occurs in the expanding tape 13, the deformation is released by the roller 43 rolling, and the expanding tape 13 Expands uniformly.

By expanding the expanding tape 13 as described above, only the excess portion 12a of the adhesive sheet 12 protruding toward the outer circumferential side of the wafer 1 is divided as shown in FIG. 7.

When dividing the excess part 12a, since it is easy to divide, at least cooling the excess part 12a is preferable. In order to cool the excess part 12a, cooling fluid, such as air cooled in the excess part 12a, can be ejected, for example directly from the surface side or via the expansion tape 13 of the back surface side. Moreover, you may employ | adopt the method of accommodating the whole expansion device 40 in a cooling chamber, and setting the atmosphere temperature in a cooling chamber about 0 degreeC-about 30 degreeC, and expanding it in the cooled state.

When the excess part 12a is segmented, as shown in FIG. 7, the chip | tip 12b of the adhesive sheet 12 arises from the excess part 12a, but these fracture chips 12b scatter on the wafer 1, Even if it is, it adheres on the protective member 11 adhering to the surface 1a of the wafer 1.

(6) protection member removal step

Next, as shown in FIG. 8, the protective member 11 arrange | positioned at the surface 1a of the wafer 1 is removed. On the surface of the removed protective member 11, broken chips 12b of the adhesive sheet 12 generated and scattered at the time of cleavage of the adhesive sheet 12 are attached, and the wafer 1 from which the protective member 11 has been removed. The surface 1a of) is in a clean state.

(7) second expansion step

Next, as shown in FIG. 9, the expanding tape 13 is expanded again by the expanding device 40. Thereby, as shown in FIG. 10, the adhesive sheet 12 is broken along the chip 3, and the chip 3 which has the adhesive sheet 12 is spaced apart.

(8) annular frame adhesion step

Next, in the state which maintained the space | interval between the individual chips 3 which the adhesive sheet 12 adhered to the back surface, respectively, as shown to Fig.11 (a), the adhesion layer of the expanding tape 13 is The annular frame 14 is adhered to the formed surface side. The annular frame 14 has a size whose inner circumference is larger than the outer circumference of the adhesive sheet 12 and which can be disposed inside the clamp member 41, and is formed of a metal plate having rigidity such as stainless steel. The annular frame 14 is adhered to the expanding tape 13 so as to be concentric with the wafer 1, whereby the plurality of chips 3 are in a state accommodated in the opening 14a of the annular frame 14.

Thereafter, as illustrated in FIG. 11B, the adhesive portion of the expanding tape 13 on the rear surface side of the annular frame 14 is cut by the cutter 50. Thereby, in the state which the several chip | tip 3 which has the adhesive sheet 12 adhere | attached on the center of the expanding tape 13 which the annular frame 14 adhered to the outer periphery shown in FIG. It is taken out from). The chip 3 is handled by using the annular frame 14, and transferred to the next step (e.g., a pickup step of picking up the chip 3 having the adhesive sheet 12 from the expanding tape 13).

(9) Effects of one embodiment

In the processing method of one embodiment according to the above, the first expansion step is performed in a state in which the protective member 11 is disposed on the surface 1a of the wafer 1, and at this time, the outer peripheral side of the wafer 1 The excess part 12a of the adhesive sheet 12 is parted. And the broken chip | tip 12b of the adhesive sheet 12 which generate | occur | produced at the time of division | segmentation is affixed on the protective member 11. As shown in FIG. After carrying out the first expansion step, since the protective member 11 with the broken debris 12b is removed from the wafer 1, the broken debris 12b is attached to the surface 1a of the wafer 1. You can stop it completely.

In this embodiment, after performing the 2nd expansion step and dividing the adhesive sheet 12 along the some chip 3, it expands in the state which maintained the space | interval between the individual chips 3 after a division | dividing ( 13 to the annular frame (14). Thereby, the expanding tape 13 is maintained in the state extended to the annular frame 14, and the space | interval between the individual chips 3 after division is maintained. Therefore, by handling the annular frame 14, the conveyance or the like can be performed without damaging the chip 3.

In addition, although the protective member 11 prevents adhesion of the fracture chips 12b of the adhesive sheet 12 to the wafer surface, it adheres to the wafer surface before the back surface grinding step, and after the back surface grinding step, the protective member ( In the case where there is other processing until the removal of 11), the protective member 11 is adhered to it, whereby the protective member 11 can be utilized as a reliably protecting the device 2. .

(10) Another embodiment

FIG. 13 shows an embodiment in which the expanding tape 13 is expanded using a different expanding device 60. That is, the first expansion step or the second expansion step can also be performed with this expanding device 60.

In this case, the expanding device 60 has a configuration in which a lifting table 63 that can be lifted and lowered by the cylinder device 62 is disposed around the cylindrical table 61, and the wafer 1 is an adhesive sheet. The annular frame 14 is set in a state where the annular frame 14 is previously adhered to the expanding tape 13 to which the wafer 1 is adhered via (12). Inside the table 61, a nozzle 64 for ejecting a cooling fluid toward the expanding tape 13 is disposed.

In the expansion of the wafer 1, first, as shown in FIG. 13A, the height position of the elevating table 63 is the same as that of the table 61, and an expansion tape is formed on the upper surface of the table 61. The wafer 1 on 13 is disposed, and the annular frame 14 is disposed on the elevating table 63. Subsequently, the annular frame 14 is fixed to the elevating table 63 with the clamp 65 provided on the elevating table 63.

And as shown in FIG.13 (b), the cylinder apparatus 62 is reduced in the state which cooled the adhesive sheet 12 by blowing cooling fluid from the nozzle 64, and the excess part of the adhesive sheet 12 is carried out. A first expansion step of dividing 12a is performed. When the lifting table 63 is lowered, the expanding tape 13 is extended outward and the excess portion 12a of the adhesive sheet 12 is divided.

Subsequently, after removing the protective member 11 from the surface of the wafer 1, as shown in FIG. 13C, the elevating table 63 is further lowered to expand the expanding tape 13, and the bonding is performed. A second expansion step of dividing the sheet 12 along the chip 3 is performed.

In this manner, the expansion device 60 can also perform the first expansion step and the second expansion step. In the first expansion step, since the protective member 11 is adhered to the surface 1a of the wafer 1, the fracture chips 12b of the excess portion 12a of the excess portion 12a of the adhesive sheet 12 generated in the first expansion step. Is not attached to the surface 1a of the wafer 1.

In addition, in this invention, although plate-shaped objects, such as the said wafer 1 divided | segmented into individual chips along the dividing | segmentation scheduled line, are the object of processing, as a method of dividing a plate-shaped part, it is the surface side like the said embodiment first. In addition to performing the back surface grinding after performing the half cut, the procedure of dividing into chips 3 by cutting and the like after back surface grinding may be adopted.

1: wafer (plate) 1a: surface of wafer
3: chip 11: protective member
12: adhesive sheet 12a: excess portion of the adhesive sheet
13: expanding tape 14: annular frame
14a: opening of the annular frame

Claims (2)

In the processing method of the plate-shaped object is arranged on the surface and divided into individual chips along the line to be divided,
An adhesive step of placing the plate-shaped article on the expanding tape via an adhesive sheet having a larger diameter than the plate-shaped article,
A first expansion step of dividing the adhesive sheet protruding at least on the outer circumferential side of the plate-shaped article by expanding the expanding tape with the protective member disposed on the surface of the plate-shaped article after the adhesion step;
A protective member removing step of removing the protective member disposed on the surface of the plate-shaped object after performing the first expansion step;
A second expansion step of breaking the adhesive sheet corresponding to the plate-shaped product along the plurality of chips by expanding the expanding tape after the protecting member is removed;
And a machining method. The method according to claim 1, wherein after performing the second expansion step, the annular frame is adhered to the expanding tape while maintaining a gap between the individual chips formed by dividing the plate, and the plate is formed in the opening of the annular frame. And an annular frame sticking step of forming a plurality of the chips formed by dividing water.

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