KR20140038297A - Machining method - Google Patents

Abstract

Provided is a machining method capable of completely preventing broken fragments of an adhesion sheet from being attached to the surface of a plate-shaped object when the plate-shaped object such as a wafer having an adhesion sheet attached on the rear surface thereof is expanded and segmented. A protective tape (11) having elastic properties is arranged on a surface (1a), and the wafer (1) segmented into each ship (3) along a division-predetermined line is arranged on an expansion tape (13) by interposing the adhesion sheet (12). The adhesion sheet (12) is continuously divided along each chip (3), and a protrusion (12a) of the adhesion sheet (12) protruding towards the outer circumference of the wafer (1) is divided (an expanding step). The protective tape (11) is removed (a protective tape removal step). The broken fragments (12b) of the adhesion sheet (12) generated when the adhesion sheet (12) is segmented are attached to the protective tape (11) so that the present invention prevents the broken fragments (12b) from being attached to the surface (1a) of the wafer (1).

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 bonded 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. Although the wafer is ground on the back and thinned to the desired thickness, a machining method is also performed in which a groove is first formed from the surface side along the division scheduled line to the desired thickness, and then separated into chips by grinding the back.

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 provided. As a method of dividing the adhesive sheet, a method of dividing the adhesive sheet by adhering an expanded 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 expanded tape or the like There is a case. In that case, the broken adhesive sheet scatters to the surface side of the wafer through the gap between the chips, and causes a problem that the adhesive sheet adheres to the device on the surface of the wafer. Moreover, such an adhesive sheet is generally formed slightly larger in diameter than a wafer, and the adhesive sheet adhered to the back surface of the wafer is partially protruded from the outer periphery of a wafer. And when employ | adopting the method of dividing an adhesive sheet by expanding an expanded tape etc., the part which protruded from the outer periphery of a wafer is also segmented, and the shavings of the protrusion part of the adhesive sheet which arose at that time adhere to the surface of a wafer, There is a problem of throwing away.

Then, 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 a wafer, and prevents the chipping of the adhesive sheet from sticking to the wafer surface is proposed (patent document 1).

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 the present invention is a processing method of a plate-shaped product in which a protective tape having elasticity is disposed on a surface thereof and is divided into individual chips along a division scheduled line, and the plate-shaped product is expanded through an adhesive sheet having a larger diameter than the plate-shaped product. An adhesive step of disposing the adhesive sheet along each chip by expanding the expanded tape with the adhesive tape disposed on the surface of the plate-shaped object after the adhesive step is disposed on the tape; After the expansion step, characterized in that it comprises a protective tape removing step of removing the protective tape disposed on the surface of the plate-shaped object.

In the processing method of the present invention, an expand step of dividing the plate into chips with a protective tape having elasticity disposed on the surface of the plate is performed, and at this time, the adhesive sheet protruding to the outer peripheral side of the plate is broken. The breaking chip | wreck of the adhesive sheet which arose at the time of breaking is affixed on a protective tape. After carrying out the expand step, since the protective tape with broken debris is removed from the plate-shaped product, the broken debris can be completely prevented from adhering to the surface of the plate-shaped object.

In the present invention, after the step of removing the protective tape, the annular frame is adhered to the expand tape while maintaining the gap between the individual chips formed by dividing the plate, the plate 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 the present invention, when a plate-like object such as a wafer having an adhesive sheet adhered to the back side is expanded and divided, a processing method is provided which can completely prevent the chippings of the adhesive sheet from adhering to the surface of the plate-shaped object. Indicates.

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 showing a protective tape adhering 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 an expand step of the processing method of the embodiment;
6 is a cross-sectional view illustrating an expand step.
7 is a cross-sectional view showing a state after an expand step.
8 is a perspective view showing a state after the expand step.
9 is a perspective view illustrating a protective tape removing step of the processing method of the embodiment;
It is sectional drawing which shows the (a) annular frame sticking step of the processing method of one Embodiment, and (b) is sectional drawing which shows the expanded tape cutting after an annular frame sticking step.
It is a perspective view which shows the state which carried out the wafer from the expander apparatus after cutting an expanded tape.
12 is a cross-sectional view showing an expander according to another embodiment, showing (a) a wafer set state and (b) an expanded step.

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 indicates 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 dividing 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 processes the said holding means 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 ° to make the division scheduled lines on the other side 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) protective tape adhesive step

Next, as shown in FIG. 2, the protective tape 11 which has elasticity is stuck to the whole surface 1a of the wafer 1 in which the groove 1d along the dividing scheduled line was formed. In this case, as the protective tape 11, an adhesive layer is formed on one surface of a synthetic resin tape such as polyvinyl chloride or polyolefin having elasticity, and the surface 1a of the wafer 1 is formed through the adhesive layer. ) And sticks.

(3) backside grinding step

Next, as shown in FIG. 3, the wafer 1 is held by the holding table 21 in accordance with the protective tape 11 side with the holding table 21, and the back surface 1b of the wafer 1 exposed on the upper side thereof. ) 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 hold | maintains a workpiece by the negative pressure effect | action by air suction on the circular horizontal holding surface formed of the porous material, and is a rotation drive mechanism not shown. Rotated around the axis by The grinding means 22 extends in the vertical direction, and the grinding wheel 25 is fixed to the distal end of the spindle 23 which is rotationally driven by a motor (not shown) via the flange 24. It is arrange | positioned so that up and down can be moved above 21). 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 obtained 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 tape 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 from the 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.

In the wafer 1, since the groove 1d of the depth reaching the completion thickness is formed along the division scheduled line in the half cut step, the grindstone 26 is grooved 1d by grinding the back surface 1b side to the completion thickness. ), And as a result the wafer 1 is divided into a plurality of chips 3 with the 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 tape 11 is adhered to the surface 1a. It arrange | positions on the expanded tape 13 through the adhesive sheet 12 of larger diameter. The expanded tape 13 is formed with an adhesive layer on one side of, for example, a synthetic resin tape having elasticity such as polyvinyl chloride or polyolefin, and in this case, has a rectangular shape or a roll shape larger than that of the wafer 1. The wound is used.

In the adhesion step, the adhesive sheet 12 made of DAF or the like is disposed in a circular shape on the adhesive layer side of the expand 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 adhere the wafer 1 to the expand sheet 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 expand tape 13. The adhesive sheet 12 is formed in a circular shape having a larger diameter than the wafer 1, and the protrusion 12a of the adhesive sheet 12 is exposed on the outer circumferential side of the wafer 1.

(5) expand phase

Next, the expand tape 13 is expanded to divide the adhesive sheet 12 along the individual chips 3.

In the expand step, the expander 40 shown in Figs. 5 and 6 is used. The expander 40 grips the end edges of the four sides of the expand tape 13, respectively, and has a clamp member 41 that is tensioned outwardly perpendicular to the end edges. The clamp member 41 is a structure which combined the cross-sectional L-shaped frame 42 in the state of up-down symmetry, and the several roller 43 is arrange | positioned near 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 expanded tape 13 is sandwiched between the upper and lower rollers 43. When the expanded tape 13 extends in the direction along the end edge in the sandwiched state, the expanded tape 13 follows the roller 43 in a rolling manner. do.

The expansion of the expand tape 13 first passes the edges of the four sides of the expand tape 13 between the upper and lower frames 42 of the clamp members 41 of the expander 40, and then the upper and lower frames. (42) is mutually close, and the expanded tape 13 is clamped by the roller 43 of the upper and lower sides. Subsequently, the clamp member 41 is moved outward (in the directions of the arrows in FIGS. 5 and 6) to expand the expand tape 13. Since the roller 43 of the clamp member 41 is held, even if a distortion inclined due to expansion occurs in the expanded tape 13, the distortion is released by the roller 43 being driven, thereby expanding the expanded tape 13. ) Expands uniformly.

By expanding the expanded tape 13 in this manner, as shown in FIG. 7, the wafer 1 is divided along the individual chips 3 to form chips 3 having the adhesive sheet 12. The space between (3) becomes wider. In addition, as the expanded tape 13 is expanded, the protrusions 12a of the adhesive sheet 12 protruding toward the outer circumferential side of the wafer 1 are simultaneously divided as shown in FIG. 8. Since the protective tape 11 is elastic, it expands with the expand tape 13, thereby widening the space between the chips 3, and allowing the adhesive sheet 12 to be divided.

In the expansion step, the adhesive sheet 12 is preferably cooled in a state in which the adhesive sheet 12 is easily broken. In order to cool the adhesive sheet 12, it is possible by spraying cooling fluids, such as air cooled from the expanded tape 13 side, for example. Moreover, you may employ | adopt the method of accommodating the whole expander 40 in a cooling chamber, and setting the atmospheric temperature in a cooling chamber about 0 degreeC-about 30 degreeC, and expanding it in the state cooled.

When the adhesive sheet 12 is divided along the individual chips 3, breakage of the adhesive sheet 12 occurs. The broken chip of the adhesive sheet 12 formed by the division tries to scatter to the surface 1a side of the wafer 1 through the gap between the chips 3, but adheres to the adhesive layer on the back surface of the protective tape 11. On the other hand, when the protrusion part 12a of the adhesive sheet 12 is parted, as shown in FIG. 8, the fracture chip | tip 12b of the adhesive sheet 12 will generate | occur | produce from the protrusion part 12a, but these fracture chips 12b are a wafer. Even if it scatters on (1), it adheres to the surface of the protective tape 11 adhering to the surface 1a of the wafer 1.

(6) step of removing protective tape

Next, as shown in FIG. 9, the protective tape 11 arrange | positioned at the surface 1a of the wafer 1 is removed. On the front and back surfaces of the removed protective tape 11, a chipped chip 12b of the adhesive sheet 12 generated and broken at the time of cleavage of the adhesive sheet 12 adheres to the wafer, and the protective tape 11 is removed. The surface 1a of (1) is in a clean state.

(7) 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.10 (a), the adhesion layer of the expanded tape 13 is The annular frame 14 is adhered to the formed surface side. The annular frame 14 has a size that the inner circumference is larger than the outer circumference of the adhesive sheet 12 and 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 expand 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 shown in FIG. 10B, the adhesive portion of the expanded 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 3 which has the adhesive sheet 12 adhered to the center of the expand tape 13 which the annular frame 14 adhered to the outer periphery shown in FIG. 40). The chip 3 is handled by using the annular frame 14, and proceeds to the next process (e.g., a pickup process of picking up the chip 3 having the adhesive sheet 12 from the expand tape 13).

(8) Effects of one embodiment

In the processing method of one embodiment according to the above, the expansion step is performed with the protective tape 11 having elasticity disposed on the surface 1a of the wafer 1, and at this time, the back surface of the wafer 1 ( The adhesive sheet 12 adhered to 1b) is divided, and the protrusion 12a of the adhesive sheet 12 on the outer circumferential side of the wafer 1 is divided. And the chippings 12b of the adhesive sheet 12 produced at the time of breaking are attached to the protective tape 11. After performing the expand step, since the protective tape 11 with the broken debris 12b is removed from the wafer 1, it is completely prevented that the broken debris 12b adheres to the surface 1a of the wafer 1. You can stop it.

In this embodiment, after performing the expanding step to divide the adhesive sheet 12 along the plurality of chips 3, the expanded tape 13 in a state in which the gap between the individual chips 3 after the division is maintained. ), The annular frame 14 is attached. Thereby, the expanded 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, conveyance etc. can be performed, without damaging the chip 3.

In addition, although the protective tape 11 prevents adhesion of the fractured debris 12b of the adhesive sheet 12 to the wafer surface, it adhere | attaches on the wafer surface before a back surface grinding step, and after the back surface grinding step, the protective tape 11 In the case of other processing until the removal of the adhesive, the protective tape 11 is adhered, thereby providing the advantage that the protective tape 11 can be utilized as the protection of the device 2.

(9) Other Embodiment

12 shows the expansion of the expand tape 13 using an expander 60 different from the above. In other words, even the expander 60 can perform the expand step.

In this case, the expander 60 has a configuration in which a lift table 63 that can be lifted and lowered by a cylinder device 62 is arranged around a cylindrical table 61, and the wafer 1 is bonded. The annular frame 14 is set in a state where the annular frame 14 is previously attached to the expand tape 13 to which the wafer 1 is attached via the sheet 12. Inside the table 61, the nozzle 64 which sprays a cooling fluid toward the expanded tape 13 is arrange | positioned.

In the expansion of the wafer 1, first, as shown in FIG. 12A, the height position of the elevating table 63 is the same as that of the table 61, and an expanded 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.12 (b), the cylinder apparatus 62 is reduced in the state which cooled the adhesive sheet 12 by blowing a cooling fluid from the nozzle 64, and chip | tip the adhesive sheet 12 is chip | tip. The expand step of dividing along (3) is performed. When the lifting table 63 descends, the expand tape 13 extends outward, the adhesive sheet 12 is divided along the chip 3, and the protrusion 12a of the adhesive sheet 12 is divided.

In this manner, the expand device 60 can also perform the expand step. In the expanding step, since the protective tape 11 is adhered to the surface 1a of the wafer 1, the fracture chips 12b of the adhesive sheet 12 generated in the expanding step are formed on the surface 1 of the wafer 1. It is not attached to 1a).

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 back surface grinding after performing the half cut from the back side, the back surface may be ground and divided into chips, and then, a protective tape having elasticity may be adhered to the surface.

1: Wafer (plate) 1a: Surface of Wafer
3: chip 11: protective tape
12: adhesive sheet 12a: protrusion of the adhesive sheet
13: expand tape 14: annular frame
14a: opening of the annular frame

Claims (2)

A method of processing a plate-shaped product in which an elastic protective tape is disposed on a surface and is divided into individual chips along a line to be divided,
An adhesion step of disposing the plate-shaped article on the expanded tape via an adhesive sheet having a larger diameter than the plate-shaped article,
An expansion step of dividing the adhesive sheet along individual chips by expanding the expand tape with the protective tape disposed on the surface of the plate-shaped product after the adhesion step;
A protective tape removing step of removing the protective tape disposed on the surface of the plate-shaped product after the expanding step
And a machining method. The method according to claim 1, wherein after the step of removing the protective tape, the annular frame is adhered to the expand tape while the plate-shaped object is maintained with a gap between the individual chips formed by dividing, and the plate-shaped opening 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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