JP2011210859A - Dicing device and dicing method - Google Patents

Abstract

Disclosed is a dicing apparatus and a dicing method capable of dicing a semiconductor wafer having a convex portion at an outer edge portion without damaging a circuit or a chip formed in the concave portion.
A dicing apparatus 1 includes a holding unit 2 that holds a wafer W via an adhesive sheet S, a separating unit 4 that separates a convex portion WA from the wafer W and the adhesive sheet S, and the convex portion WA is separated. And a cutting means 7 for forming a cut in the wafer W ′.
[Selection] Figure 1

Description

  The present invention relates to a dicing apparatus and a dicing method.

Semiconductor wafers (hereinafter sometimes simply referred to as wafers) on which circuits such as ICs (Integrated Circuits) and LSIs (Large Scale Integrations) are formed on one side are used to reduce the size and weight of electronic devices. Before being divided into a thickness of about 50 μm. However, when the wafer is thinned in this way, its own rigidity is lost, and handling in subsequent processes becomes difficult. Thus, a wafer processing method for facilitating handling during processing has been studied (see, for example, Patent Document 1). In this wafer processing method, a wafer including a circuit formation region where a circuit is formed and an outer peripheral surplus region surrounding the circuit formation region is processed as follows. That is, a concave portion is formed in a region corresponding to a circuit formation region on the back surface of the wafer, and an outer peripheral surplus region is made thicker than the circuit formation region to form a ring-shaped reinforcing portion (hereinafter referred to as a convex portion). Increased rigidity.
And after performing the additional process process which consists of a film formation process etc. with respect to this wafer, the convex part is removed by grinding and cutting.

JP 2007-19379 A

  However, when the convex portion is removed by grinding, the convex portion must be flush with other regions, and a high degree of accuracy is required. On the other hand, as shown in FIGS. 3A and 3B, when the convex portion WA is removed by cutting, the wafer W is moved in the direction of the arrow with respect to the rotating blade 78B that cuts in a straight line instead of an arc shape. (In addition, in order to show the positional relationship with the cutting area K at the time of cutting, in FIG. 3 (A), in FIG. This is illustrated in FIG. For this reason, the width E2 of the cutting region K becomes larger than the thickness E1 of the rotating blade 78B, and the chip close to the outer edge of the bottom surface WB is damaged, and a large amount of cutting powder is formed on the chip. There is a problem of damaging the circuit surface. In view of the above, it is desired to develop a dicing apparatus capable of removing convex portions without damaging circuits and chips without requiring high precision.

  An object of the present invention is to provide a dicing apparatus and a dicing method capable of removing a convex portion with a simple configuration without damaging a circuit or a chip even in a semiconductor wafer having a convex portion on an outer edge portion.

  In order to achieve the above object, the dicing apparatus according to the present invention is intended for a semiconductor wafer having an annular convex portion protruding in one of the thickness directions at the outer edge and a bottom surface inside the convex portion. A dicing apparatus for cutting into a predetermined size, wherein the semiconductor wafer has an adhesive sheet affixed on one side thereof, holding means for holding the semiconductor wafer via the adhesive sheet, the semiconductor wafer, and the adhesive sheet A configuration is provided in which a separating unit that separates the convex portion from the above and a cutting unit that forms a cut in the semiconductor wafer from which the convex portion is separated are employed.

At this time, it is preferable that the dicing apparatus of the present invention is configured to include a removing unit that peels and removes the separated convex portions from the adhesive sheet.
Furthermore, in the dicing apparatus of the present invention, the adhesive sheet is an energy ray curable adhesive sheet, and includes an energy ray irradiating means for irradiating the adhesive sheet affixed to the convex surface with an energy ray. preferable.

  In addition, the dicing method of the present invention has a predetermined size for a semiconductor wafer having an annular convex portion protruding in one direction in the thickness direction at the outer edge portion and a bottom surface inside the convex portion. A dicing method for cutting, wherein the semiconductor wafer is held via an adhesive sheet affixed to one side of the semiconductor wafer, the convex portion is separated from the semiconductor wafer and the adhesive sheet, and the convex portion is separated A configuration is employed in which a cut is formed in the formed semiconductor wafer.

According to the invention as described above, the convex portion is moved relative to the holding means for holding the semiconductor wafer and separated, so that a high degree of accuracy is not required when separating the convex portion. Can do. In addition, since a wide cutting region is not formed in the concave portion of the semiconductor wafer, chips formed near the outer edge of the concave portion are not damaged. Furthermore, since no cutting powder is generated, the circuit surface formed on the chip with the cutting powder is not damaged. Therefore, the wafer can be diced by removing the protrusions without damaging the chip or the circuit surface.
Further, if the holding means is composed of the bottom surface holding means and the outer side holding means, the bottom surface of the concave portion and the convex portion can be reliably moved relative to each other, so that the concave portion can be prevented from being damaged during separation of the convex portion.
Further, by having a removing means for removing the separated convex portions, it is possible to remove the convex portions that become an obstacle during the dicing prior to the dicing step.
Furthermore, when the adhesive sheet is an energy ray curable sheet, the adhesive sheet on the surface of the convex portion is cured by irradiating the adhesive sheet attached to the surface of the convex portion with the energy ray irradiating means to cure the convex portion surface. Can be easily peeled off, and the convex portion can be easily and reliably removed.

The fragmentary sectional view of the dicing device concerning the embodiment of the present invention. (A), (B) is operation | movement explanatory drawing of the dicing apparatus of embodiment. Explanatory drawing of the convex part removal method by the conventional cutting.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, the dicing apparatus 1 removes the convex portion WA formed on the outer edge portion of the wafer W, and then forms a lattice-like cut in the wafer W, singulated into chips WE having a predetermined shape (FIG. 2 ( B) see). Note that the target wafer W is, for example, as described in Patent Document 1, an inner peripheral portion is thinly ground with respect to the outer edge portion, so that an annular shape protruding in the thickness direction (back side) is obtained. The convex portion WA is formed on the outer edge portion, the inner side surrounded by the convex portion WA is the bottom surface WB, and a circuit is formed on the surface (the opposite surface of the grinding surface, the upper surface in FIG. 1) WD. ing. The convex portion WA is an inner peripheral surface WA1 orthogonal to the bottom surface WB, a convex top surface WA2 orthogonal to the inner peripheral surface WA1, an outer peripheral surface WA3 of the wafer W, and an outer peripheral side region of the surface WD. It consists of a convex back surface WA4 facing away from the top surface WA2. The wafer W has an adhesive sheet S such as a mounting tape attached to the entire back surface, that is, the entire convex top surface WA2, inner peripheral surface WA1, and bottom surface WB, and the ring frame RF is connected to the wafer W via the adhesive sheet S. It is integrated. For the adhesive sheet S, an energy ray curable adhesive that is cured by energy rays such as ultraviolet rays and whose adhesive strength is reduced is employed.

  The dicing apparatus 1 includes a holding unit 2 that holds the wafer W via the adhesive sheet S, a separation unit 4 that separates the convex portion WA from the wafer W and the adhesive sheet S, and a semiconductor wafer W ′ from which the convex portion WA is separated. (See FIG. 2A) and a cutting means 7 for forming a grid-like cut.

  The holding means 2 includes a side wall portion 22 and a bottom wall portion 23 and includes a cylindrical central concave portion 21 opened upward. The side wall portion 22 is provided with a concave groove portion 24 opened upward along the outer periphery. In addition, a transparent member made of a glass plate or the like that faces the lower portion of the top surface WA2 of the convex portion and is capable of transmitting energy rays such as ultraviolet rays while being flat with the upper surface of the side wall portion 22 in the opening of the concave groove portion 24. 25 is provided. The upper surface of the side wall portion 22 and the upper surface of the transmissive member 25 constitute a convex portion abutting portion 26 on which the adhesive sheet S affixed to the convex portion top surface WA2 abuts. In addition, an ultraviolet lamp 27 as an energy beam irradiation means is built in the concave groove portion 24. Furthermore, outside holding means 28 that is located outside the projection WA and can hold the adhesive sheet S and the ring frame RF is provided outside the projection contact part 26. A plurality of suction ports 29 are formed on the upper surface of the outer holding means 28, and these suction ports 29 are connected to a suction device (not shown) via a chamber 30 formed inside the holding means 2.

The separating means 4 protrudes from the wafer W by relatively moving the bottom face holding means 40 holding the bottom face WB via the adhesive sheet S, and the bottom face holding means 40 and the convex portion abutting portion 26 in the vertical direction in the figure. The moving means 50 for separating the part WA, the pressing means 60 for pressing the surface WD of the wafer W, and the removing means 8 for peeling and removing the separated convex part WA from the adhesive sheet S are provided.
The bottom surface holding means 40 is formed in substantially the same planar shape as the entire area of the bottom surface WB. A plurality of suction ports 41 for adsorbing and holding the bottom surface WB are formed on the top surface of the bottom surface holding means 40 via a bottom surface pasting portion S1 that is a portion pasted on the bottom surface WB of the adhesive sheet S. The mouth 41 is connected to a suction device such as a suction pump (not shown) via a chamber 42 formed in the bottom surface holding means 40.

The moving means 50 includes a linear motion motor 51 as a drive device, the motor main body 52 is fixed to the bottom wall portion 23, and the output shaft 53 is connected to the lower surface of the bottom surface holding means 40 in FIG. Accordingly, the convex portion WA can be separated from the wafer W by relatively moving the holding unit 2 and the bottom surface holding unit 40 in a direction orthogonal to the bottom surface WB of the wafer W.
The holding means 60 has a support 61 formed in a disc shape in accordance with the planar shape of the bottom surface WB of the wafer W, and is formed in an annular shape along the outer peripheral edge of the lower surface in FIG. A contact member 62 that can contact the WD, and a linear motion motor 63 that is supported by a frame (not shown) and moves the support 61 up and down in FIG. By operating in synchronization with the motor 51, the convex portion WA can be separated from the wafer W. A plurality of holes or annular holes are formed on the outer peripheral side of the contact member 62 in the support body 61 and connected to a suction source (not shown) to suck and remove dust such as dust and debris of the wafer W. A suction hole 61A as a dust removing means is provided. The dust removing means is not limited as long as the dust is removed. For example, the dust removing means may be removed by adhering the dust with an adhesive tape, or a gas such as air or nitrogen is blown to the wafer W side. It may be configured to remove dust. Further, not only the outer peripheral side of the contact member 62 but also the inner side of the contact member 62 may be provided. Although the contact member 62 is not particularly limited, the contact member 62 is configured by an elastic member such as rubber or resin, and is located inside the boundary region with the convex back surface WA4 on the surface WD of the wafer W, and is supported by the bottom surface. A bottom WB region is provided between the means 40 and the means 40 so as to be sandwiched therebetween. The contact member 62 may be formed in a disc shape (solid shape) in accordance with the planar shape of the bottom surface WB other than the annular shape. Further, the abutting member 62 may be configured by an inelastic member such as a metal.

  The removing means 8 is a bracket 80A provided on the upper surface of the support 61 in FIG. 1, and a shaft that is slidable in the vertical direction in FIG. 1 with respect to the bracket 80A and that prevents the bracket 80A from falling off. A shaft 80C having an end 80B, an urging means 80D configured by a spring for urging the shaft 80C downward in FIG. 1, and a suction means such as a suction pump (not shown) are connected to the shaft 80C. 1, a suction pad 80 </ b> E attached to the lower side.

  The cutting means 7 includes a first single-axis robot 9 as a driving device that supports the holding means 2 so as to be movable in the left-right direction in FIG. 1, and a second single-axis robot 71 as a driving device that extends in the direction perpendicular to the paper surface in FIG. A rotary motor 73 as a driving device provided on the slider 72 of the second single-axis robot 71 and having an output shaft (not shown) that can rotate around the vertical axis in FIG. 1, and the rotary motor 73 (not shown). A linear motion motor 74 as a driving device provided on the output shaft and having an output shaft 75 that can be expanded and contracted in the vertical direction, and a shaft provided in the output shaft 75 of the linear motion motor 74 and extending in the left-right direction in FIG. A rotary motor 76 as a drive device having a rotatable output shaft 77, and a rotary blade 78 provided on the output shaft 77 of the rotary motor 76.

  In the above dicing apparatus 1, as a procedure for dicing the wafer W, first, the wafer W integrated with the ring frame RF is conveyed by the conveying means (not shown) via the adhesive sheet S, and the bottom surface is held on the bottom surface holding means 40. When the WB is positioned, the convex top surface WA2 is positioned on the convex contact portion 26, and the ring frame RF is positioned on the outer holding means 28, and is supported on the holding means 2. Next, the holding means 2 drives a suction device (not shown) to suck air from the suction ports 29 and 41, sucks and holds the bottom surface WB by the bottom face holding means 40 through the adhesive sheet S, and also the outer holding means 28. Thus, the adhesive sheet S and the ring frame RF outside the convex portion WA are sucked and held. Then, the ultraviolet lamp 27 emits light, thereby curing the adhesive of the part of the adhesive sheet S attached to the top surface WA2 of the convex portion and reducing its adhesive force.

  Next, as shown in FIG. 2A, the linear motion motor 63 is driven to bring the contact member 62 and the suction pad 80E into contact with the surface WD of the wafer W. Thereafter, the linear motion motor 51 and the linear motion motor 63 are driven synchronously while the suction port 41 holds the bottom surface WB and the ring frame RF by suction, and the contact member 62 and the bottom surface holding means 40 are moved to the convex contact portion. 26, the boundary between the front surface WD of the wafer W and the convex back surface WA4 is broken, and the convex portion WA is separated from the wafer W. At this time, the wafer W may be broken and dust may be generated. However, since the dust can be sucked and removed by the suction hole 61A, the inconvenience of dust adhering to the surface WD of the wafer W is avoided. be able to. The suction pad 80E is pushed upward in the figure against the biasing force of the biasing means 80D, and at the same time, a suction force is applied by a suction means (not shown) to suck and hold the convex portion WA. Next, when the linear motion motor 63 is driven, the contact member 62 and the suction pad 80E are separated from the surface WD of the wafer W in a state where the convex portion WA is sucked and held. At this time, since the convex portion WA is irradiated with the ultraviolet rays on the adhesive sheet S portion attached to the convex top surface WA2, the convex portion WA can be easily peeled off from the adhesive sheet S and removed.

  Next, as shown in FIG. 2B, a notch reaching the adhesive sheet S is formed from the surface WD side of the wafer W ′ from which the convex portion WA has been removed by the rotating blade 78, and the wafer W ′ is formed into a plurality of chips WE. It is divided into pieces. Specifically, the first single-axis robot 9 and the second single-axis robot 71 are controlled so that the surface of the rotating blade 78 is slightly parallel to the direction perpendicular to the paper surface in FIG. It is positioned on the right side and above the end on the back side (hereinafter referred to as the rear side) in FIG. Next, the rotary blade 78 driven to rotate by the rotary motor 76 is lowered to a position in contact with the adhesive sheet S, and the second single-axis robot 71 moves the rotary blade 78 to the front side (hereinafter referred to as the front side) in FIG. As a result, a notch in the front-rear direction along the street formed in the wafer W ′ (hereinafter referred to as a front-rear notch) is formed. Thereafter, each time the holding means 2 is sequentially moved to the left side, the same operation as the above-described front-rear cut formation operation is repeated to form a plurality of front-rear cuts arranged in the left-right direction, and the wafer W 'is diced.

When the formation of the front and rear cuts is completed, a cut in the left and right direction (hereinafter referred to as a left and right cut) is formed. In the formation of the left and right cuts, the rotary blade 73 is rotated 90 degrees by the rotary motor 73 and the first single-axis robot 9 and the second single-axis robot 71 are controlled so that the rotary blade 78 is slightly moved from the rear end of the wafer W ′. It is located on the front side and above the left end. Then, the rotating blade 78 that is being rotated is lowered to a position in contact with the adhesive sheet S, and the holding unit 2 is moved to the left by the first single-axis robot 9, whereby left and right along the street formed on the wafer W ′. Make a notch. Thereafter, each time the rotating blade 78 is sequentially moved forward, the same operation as the left and right cuts is repeated, and a plurality of left and right cuts arranged in the front-rear direction are formed and diced.
In addition, the formation procedure of the front and rear cuts and the left and right cuts is not limited to the above-described procedure, and other procedures may be appropriately formed.

  According to the embodiment as described above, since the protrusion WA is separated by moving relative to the holding means 2 that holds the wafer W, the outer edge of the wafer W ′ is separated as in the configuration in which the protrusion WA is separated by cutting. The chip formed nearby is not damaged, and the cutting powder is not generated, so the circuit is not damaged by the cutting powder. Therefore, the wafer W ′ can be diced by the cutting means 7 without damaging the chip or the circuit surface.

  As described above, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but without departing from the spirit and scope of the invention, Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations. In addition, the description of the shape, material, and the like disclosed above is exemplary for ease of understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

For example, in the embodiment, in order to form both the front and rear cuts and the left and right cuts with one rotary blade 78, the rotary blade 78 can be rotated around an axis extending in the vertical direction. You may rotate around an axis. Moreover, you may provide the rotation blade only for front-and-back cutting, and the rotation blade only for left-right cutting.
Further, the cutting means may use a laser other than the rotating blade to form a cut in the wafer W, or the street may be made brittle by the laser.
Furthermore, the energy beam irradiation means (ultraviolet lamp 27) in the embodiment is not an essential requirement of the present invention and can be omitted.
In the above embodiment, the holding means 2 is configured to hold the wafer W by suction. However, in the present invention, the means for holding the wafer W is not limited to suction holding, and for example, holding using a chuck means, etc. Other suitable holding means can be used. Similarly, as the supporting means other than the suction holding, the removing means 8 can also be applied with an appropriate convexity such as attaching another adhesive sheet or the like to the convex portion and pulling it, or engaging and pulling the convex portion with the engaging means. Part support means are available.

Furthermore, in the embodiment, the removing unit 8 is attached to the presser unit 60. However, the remover unit 8 may be separated from the presser unit 60 and configured to be operable independently.
The wafer W may be a silicon semiconductor wafer or a compound semiconductor wafer.
Furthermore, the upper surface of the bottom surface holding means 40 may be configured to be able to transmit energy rays, and the energy beam irradiation means similar to that of the above embodiment may be disposed in the chamber 42. Thereby, each chip WE can be easily picked up from the adhesive sheet S.
Further, the energy beam irradiation means is not limited to the device that irradiates ultraviolet rays, and any device that irradiates an appropriate energy beam such as an electron beam to cure the adhesive sheet may be used.
Furthermore, the drive device in the embodiment employs an electric device such as a rotation motor, a linear motion motor, a single axis robot, an articulated robot, an actuator such as an air cylinder, a hydraulic cylinder, a rodless cylinder, and a rotary cylinder. (Some overlap with those exemplified in the embodiment).

DESCRIPTION OF SYMBOLS 1 ... Dicing apparatus 2 ... Holding means 4 ... Separation means 7 ... Cutting means 8 ... Removal means 27 ... Ultraviolet lamp (energy ray irradiation means)
S ... Adhesive sheet W ... Semiconductor wafer WA ... Convex part WB ... Bottom

Claims (4)

A dicing apparatus for cutting a semiconductor wafer having an annular convex portion protruding in one of the thickness directions at an outer edge portion and having a bottom surface on the inner side surrounded by the convex portion, to a predetermined size,
The semiconductor wafer has an adhesive sheet attached to one side,
Holding means for holding the semiconductor wafer via the adhesive sheet;
Separating means for separating the convex portion from the semiconductor wafer and the adhesive sheet;
A dicing apparatus comprising: cutting means for forming a cut in the semiconductor wafer from which the convex portions are separated.   The dicing apparatus according to claim 1, further comprising a removing unit that peels and removes the separated convex portions from the adhesive sheet. The adhesive sheet is an energy ray curable adhesive sheet,
The dicing apparatus according to claim 1, further comprising an energy ray irradiating unit that irradiates the adhesive sheet affixed to the surface of the convex portion with an energy ray. A dicing method for cutting a semiconductor wafer having an annular convex portion protruding in one of the thickness directions at the outer edge portion and having a bottom surface on the inner side surrounded by the convex portion.
Holding the semiconductor wafer via an adhesive sheet affixed to one of the semiconductor wafers,
Separating the protrusions from the semiconductor wafer and the adhesive sheet;
A dicing method, wherein a notch is formed in a semiconductor wafer from which the convex portions are separated.

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