JP2010177566A - Annular frame for supporting work and work transfer method - Google Patents

Abstract

A work supported on an annular frame (first annular frame) via an adhesive tape is divided into a large number of chips by expanding the adhesive tape, and then transferred to an expanded adhesive tape. When a small second annular frame is attached and the adhesive tape is cut out by a cutting tool at the second annular frame, the cutting tool is prevented from being worn.
An annular groove 21c is formed on a sticking surface 21b of an adhesive tape 10 of a second annular frame (small-diameter frame) 21 so that the tip of the cutter 40 does not come into contact with the inner surface of the groove 21c. The adhesive tape 10 is penetrated and inserted into the groove 21c. While maintaining this state, the cutter 40 is rotated once along the groove 21c, and the adhesive tape 10 is cut out in a circular shape. Since the cutter 40 is not brought into contact with the small-diameter frame 21, the cutter 40 is not worn.
[Selection] Figure 7

Description

  The present invention relates to an annular frame for supporting a workpiece and a workpiece transfer method which are preferably employed when an adhesive tape to which a workpiece such as a semiconductor wafer is attached is expanded to divide the workpiece into a plurality of chips.

  In the semiconductor device manufacturing process, a large number of rectangular areas are defined on the surface of a disk-shaped semiconductor wafer by grid-like division lines, electronic circuits such as IC and LSI are formed on the surface of these rectangular areas, and then the back surface After performing necessary processing such as polishing after grinding, all the divided lines are cut, that is, diced to obtain a large number of semiconductor chips. The semiconductor chip thus obtained has a film adhesive for die bonding called DAF (Die Attach Film) having a thickness of, for example, several μm to 100 μm, formed of an epoxy resin on the back surface. The DAF is bonded to the die bonding frame that supports the semiconductor chip by heating through the DAF.

  On the other hand, as a method for dividing a plate-shaped workpiece such as a semiconductor wafer, in recent years, a laser processing method has been attempted in which a laser beam is irradiated with a focusing point inside the workpiece. . In the dividing method using this laser processing method, a pulsed laser beam in the infrared region having transparency is irradiated from the one surface side of the work piece with the converging point inside to irradiate the inside of the work piece. In order to divide the workpiece by applying an external force to the division line that has been reduced in strength due to the formation of this alteration layer. Reference 1). As means for applying the external force, means for expanding the workpiece simultaneously by expanding an adhesive tape such as a protective tape attached to the back surface of the workpiece is employed.

  Such a method of dividing a workpiece by laser processing can be applied to a semiconductor wafer to which the DAF is attached. In that case, the adhesive tape is attached to the DAF attached to the back surface of the semiconductor wafer. The DAF is divided together with the semiconductor chip by the expansion of the adhesive tape. By the way, the semiconductor wafer divided into a large number of semiconductor chips due to the expansion of the adhesive tape is transported to the next step. During the transportation, the expanded adhesive tape is loosened so that adjacent semiconductor chips are separated. In some cases, there were problems such as rubbing and damage, and split DAF joining again.

  Therefore, it has been proposed that the adhesive tape is left in a state where tension is applied by expansion, thereby maintaining the distance between the semiconductor chips and preventing contact between the semiconductor chips (Patent Document 2). That is, in Patent Document 2, the semiconductor wafer is divided into a large number of semiconductor chips by expanding the adhesive tape in a state where the semiconductor wafer before division is supported by the opening of the annular frame via the adhesive tape. Then, while maintaining the divided state of the semiconductor wafer, the annular transfer frame is attached to the adhesive tape inside the annular frame, and the adhesive tape attachment portion on the back surface of the transfer frame is annularly cut. . Thereby, the semiconductor wafer in which the space | interval between semiconductor chips is maintained is supported by the opening part of the transfer flame | frame via the adhesive tape of the state to which the tension | tensile_strength was provided.

Japanese Patent No. 3408805 JP 2008-140874 A

  In order to cut the adhesive tape attached to the rear surface of the transfer frame as described above, the cutting edge of the cutter (the cutting edge in the above-mentioned document 2) abutted against the transfer frame from the adhesive tape side is relatively surrounded. This is done by moving one or more rounds in the direction. However, this method has a problem that the cutting edge of the cutter is likely to be worn because it is in sliding contact with the transfer frame, which causes troublesome replacement of the cutter and an increase in cost. In addition, uncut cutting may occur without achieving the cutting edge of the cutter reliably penetrating through the adhesive tape.

  Therefore, the present invention makes it difficult for the cutter blade edge to wear, thereby improving the maintainability and suppressing the cost rise, and can reliably cut out the adhesive tape, thereby improving the productivity. An object is to provide an annular frame for supporting a workpiece and a workpiece transfer method.

  The work-supporting annular frame of the present invention is an annular frame that supports a plate-like work disposed in an opening via an adhesive tape that is attached to an attachment surface, and the adhesive tape is attached thereto. An annular groove that allows the cutting tool to be inserted in a non-contact state is formed on the sticking surface.

  According to the annular frame of the present invention, when the adhesive tape that covers the groove and is adhered to the attachment surface is cut out in a circular shape, the cutting tool is relatively moved along the groove with the cutting tool inserted in the groove. By moving, the adhesive tape can be cut out in a circular shape. Wearing the cutting tool can be suppressed by making the cutting tool non-contact with the inner surface of the groove. For this reason, the life of the cutting tool is extended, maintenance is improved, and cost increases are suppressed. Moreover, since the cutting tool inserted in the groove part completely penetrates the adhesive tape, the adhesive tape can be cut reliably and no uncut portion is generated, resulting in improved productivity.

  Next, the workpiece transfer method of the present invention is a plate-like workpiece that is arranged in the opening of the first annular frame and is divided into a plurality of chips supported by the first annular frame via an adhesive tape. Is transferred to a second annular frame having an outer edge smaller than the inner edge of the first annular frame, and the workpiece of the adhesive tape is stuck inside the opening of the first annular frame. An adhesive tape expanding step for expanding the region, and the groove portion of the second annular frame in which an annular groove portion is formed in the annular region between the inner edge of the first annular frame and the outer edge of the workpiece of the adhesive tape. A second annular frame adhering step for adhering the surface formed with the cutting tool, a cutting tool inserting step for inserting the cutting tool into the groove portion in a non-contact state, and the cutting tool relatively moving along the groove portion Let the adhesive tape be circular Wherein the adhesive tape cutout step unplugging Ri, the second annular frame is characterized in that an annular frame according to the present invention. According to the workpiece transfer method of the present invention, by using the annular frame according to the present invention, the above-described effects obtained by the annular frame can be obtained in the same manner.

  The work referred to in the present invention is not particularly limited. For example, a semiconductor wafer such as a silicon wafer, in which grooves or an internal deteriorated layer are formed in a division line to be divided into a large number of chips, or such Examples include those in which the DAF is adhered to a wafer, and such wafers in which the line to be divided is fully cut and the DAF is half-cut (cut to the middle of the thickness). .

  According to the present invention, it becomes difficult for the cutting tool to be worn, thereby improving the maintainability and suppressing the cost increase, and it is possible to reliably cut out the adhesive tape, thereby improving the productivity. There are effects such as.

It is a perspective view which shows the process of the workpiece transfer method which concerns on one Embodiment of this invention in order of (a)-(c). (A) The perspective view of the state which supported the wafer with the small diameter flame | frame, (b) The perspective view which shows the back surface side of a small diameter flame | frame. It is sectional drawing which shows the initial state of the tape expansion operation by a tape expansion apparatus. It is sectional drawing which shows a state when an adhesive tape is expanded with the tape expansion apparatus. It is sectional drawing which shows the state which stuck the small diameter flame | frame on the adhesive tape expanded with the tape expansion apparatus. It is sectional drawing which shows the state which has picked up the wafer transferred to the small diameter flame | frame from the tape expansion apparatus. It is sectional drawing which shows the process of cutting out the adhesive tape stuck to the small diameter flame | frame in order of (a)-(c).

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
(1) Semiconductor wafer FIG. 1 shows a procedure of a workpiece transfer method according to an embodiment in the order of (a) to (c). 1 is a disk-shaped semiconductor wafer thinned to a thickness of, for example, about 100 to 700 μm, such as a silicon wafer. In this wafer 1, a large number of rectangular semiconductor chips 3 are partitioned by grid-like division planned lines 2. An electronic circuit (not shown) such as an IC or an LSI is formed on the surface of each chip 3. The DAF for die bonding may be attached to the back surface of the wafer 1 in some cases.

  The wafer 1 is subjected to dicing processing on the division line 2 and then expanded in the radial direction so as to be divided along the division line 2 and divided into chips 3. The dicing process in this case is a preliminary process for dividing the wafer 1 into individual chips 3, and means such as cutting or laser processing is employed.

  As the cutting process in the dicing process, the dicing process in which the back surface is ground after the half cut for forming the groove in the division line 2 on the front surface side, the DAF is attached to the back surface of the wafer 1, etc. For example, a process of completely cutting only the wafer 1 from the surface side is conceivable. On the other hand, in the laser processing, by applying a pulsed laser beam having transparency to the inside of the wafer 1 with a converging point being irradiated, a deteriorated layer is formed along the planned dividing line 2 to reduce the intensity of the planned dividing line 2. And a method of performing ablation processing along the planned dividing line 2 are conceivable.

  When the wafer 1 is diced, as shown in FIG. 1A, the wafer 1 is opened through an adhesive tape 10 inside a first annular frame (hereinafter referred to as a large diameter frame) 11. 11a is supported. The large-diameter frame 11 is made of a metal plate having rigidity such as stainless steel, and the adhesive tape 10 is attached to the back surface of the large-diameter frame 11 so as to cover the opening 11a. The pressure-sensitive adhesive tape 10 has a pressure-sensitive adhesive layer formed on one surface of a stretchable base material, and the pressure-sensitive adhesive layer is attached to the back surface of the large-diameter frame 11. Examples of the base material of the pressure-sensitive adhesive tape 10 include synthetic resin sheets such as polyvinyl chloride, polypropylene, polyethylene, and polyolefin, and examples of the pressure-sensitive adhesive layer include acrylic resins.

  The wafer 1 is disposed concentrically in the opening 11 a of the large-diameter frame 11, and the back side is attached to the adhesive layer of the adhesive tape 10. As a result, the wafer 1 is integrally supported by the large-diameter frame 11 via the adhesive tape 10. The wafer 1 is transported to the dicing process by handling the large-diameter frame 11.

(2) Dividing the wafer and transferring it to a small-diameter frame After dicing, the wafer 1 is expanded in the radial direction and divided into a large number of chips 3 as described above. It is done at the same time. After the wafer 1 is divided into a large number of chips 3, as shown in FIGS. 1B to 1C, the wafer 1 is changed from the large diameter frame 11 to a small diameter frame (one size smaller than the large diameter frame 11) The second annular frame 21 is transferred to and supported by the small-diameter frame 21. 2A shows a state in which the wafer 1 is supported by the small-diameter frame 21, and FIG. 2B shows the back surface 21 b side, which is the attachment surface of the small-diameter frame 21 to the adhesive tape 10.
First, a method for expanding the adhesive tape 10 and dividing the wafer 1 into a large number of chips 3 will be described.

(2-1) Dividing the Wafer FIG. 3 shows a tape expansion device suitable for expanding the adhesive tape 10. This tape expansion apparatus has a frame holding table 31 that can move up and down. As the frame holding table 31 is raised, the large-diameter frame 11 is sandwiched between the frame holding table 31 and the frame pressing plate 32 as shown in FIG. 3, and the wafer 1 is floated in the air. Retained.

  Next, a cylindrical push-up member 33 disposed below the wafer 1 is lifted by a driving device (not shown) and comes into contact with the lower surface of the adhesive tape 10 attached to the wafer 1. 33 rises and the wafer 1 is positioned at a higher tape expansion position than the large-diameter frame 11 as shown in FIG. 4 (adhesive tape expansion process). In addition, a cutter (cutting tool) 40 for cutting the adhesive tape 10 is disposed in the push-up member 33 with the blade edge facing upward, as will be described later.

  In the process of reaching the expansion position, the adhesive tape 10 attached to the back surface of the wafer 1 expands by receiving a force pulled in the radial direction. Then, as the adhesive tape 10 expands in the radial direction, the wafer 1 is divided along the division line 2 on which dicing is performed and divided into individual chips 3. There is a slight gap between the chips 3 due to the expansion of the adhesive tape 10. In addition, when DAF is affixed on the back surface of the wafer 1, DAF is also divided | segmented for every chip | tip 3 in the state adhered to each chip | tip 3. FIG.

(2-2) Transfer of Wafer to Small Diameter Frame The wafer 1 divided into a large number of chips 3 is transported to the next process (for example, a pickup process for taking out the chips 3 from the adhesive tape 10). However, there is a case where the chip 3 is damaged as described above if it is expanded. That is, the wafer 1 divided into a large number of chips 3 can be taken out from the tape expansion device by lowering the frame holding base 31 and the push-up member 33 from the state shown in FIG. As a result, the adjacent chips 3 may rub against each other and be damaged.

  Therefore, in the present embodiment, as shown in FIG. 5, between the inner edge of the large-diameter frame 11 and the outer edge of the wafer 1 in the adhesive tape 10 with the push-up member 33 raised and the adhesive tape 10 being expanded. The small-diameter frame 21 is stuck to the annular region 10a (small-diameter frame sticking step). The small-diameter frame 21 is an annular frame whose inner diameter is larger than the outer diameter of the divided wafer 1 and whose outer diameter is smaller than the inner diameter of the large-diameter frame 11. It is made of a metal plate.

  In this case, the small-diameter frame 21 has a smaller diameter than the push-up member 33, and is concentric with the wafer 1 on the upper surface of the horizontal annular portion of the adhesive tape 10 between the wafer 1 and the push-up member 33 after division. Affixed to. FIG. 1B and FIG. 7A show a state where the small-diameter frame 21 is attached to the adhesive tape 10. As shown in FIG. 2B and FIG. 7, the small-diameter frame 21 of the present embodiment has an annular groove portion 21 c having a V-shaped cross section formed concentrically on the back surface 21 b that is an attachment surface to the adhesive tape 10. Has been. The cutter 40 is disposed below the groove portion 21c so as to be movable up and down. When the cutter 40 is raised, the cutting edge at the tip is set to be insertable into the groove portion 21c.

  Next, as shown in FIG. 7 (b), the cutter 40 disposed inside the push-up member 33 is raised, and the tip of the cutter 40 is attached to the back surface of the small-diameter frame 21. It stabs and inserts in the arbitrary location of the groove part 21c (cutting tool insertion process). At this time, the state where the tip of the cutter 40 does not contact the inner surface of the groove 21c is maintained. Next, the cutter 40 is moved once in the circumferential direction along the groove portion 21c while not contacting the inner surface of the groove portion 21c (adhesive tape cutting step). Thereby, as shown in FIG.7 (c), the adhesive tape 10 is cut | disconnected along the groove part 21c, and is cut out circularly. If possible, the adhesive tape 10 may be cut by the cutter 40 by rotating the adhesive tape 10 side instead of moving the cutter 40 in the circumferential direction.

  When the adhesive tape 10 is cut out in this manner, the divided wafer 1 that has been divided into a large number of chips 3 is expanded into the opening 21a of the small-diameter frame 21 and is still in a state where tension is applied. 10 and can be picked up from the expansion device as shown in FIG. Since the adhesive tape 10 is in the expanded state, the interval between the divided chips 3 is maintained, and therefore, when the small-diameter frame 21 is conveyed, the chips 3 do not come into contact with each other and the chips are prevented from being damaged.

(3) Effects of One Embodiment According to the one embodiment, when the adhesive tape 10 attached to the small-diameter frame 21 is cut out by the cutter 40, the cutter 40 is inserted into the groove portion 21c and the groove portion 21c is inserted. Since the inner surface is not contacted, wear of the cutter 40 can be suppressed. For this reason, the life of the cutter 40 is extended, so that the maintainability is improved and the cost increase is suppressed. Further, since the cutter 40 inserted into the groove portion 21c completely penetrates the adhesive tape 10, the adhesive tape 10 can be reliably cut and no uncut portion is generated, and as a result, productivity is improved.

1 ... Semiconductor wafer (work)
2 ... Line to be divided 3 ... Semiconductor chip 10 ... Adhesive tape 11 ... Large diameter frame (first annular frame)
11a: opening of large diameter frame 21 ... small diameter frame (second annular frame)
21a: Opening of small diameter frame 21b: Back surface of small diameter frame (adhesive surface of adhesive tape)
21c ... Slot of small-diameter frame 40 ... Cutter (cutting tool)

Claims (2)

An annular frame that supports a plate-like workpiece disposed in the opening via an adhesive tape that is attached to the attachment surface,
An annular frame for supporting a workpiece, characterized in that an annular groove portion on which a cutting tool can be inserted in a non-contact state is formed on the attachment surface to which the adhesive tape is attached. A plate-like workpiece that is arranged in the opening of the first annular frame and is divided into a plurality of chips supported by the first annular frame via an adhesive tape is made to be more than the inner edge of the first annular frame. A workpiece transfer method to be supported again on a second annular frame having a small outer edge,
An adhesive tape expansion step for expanding an area where the workpiece of the adhesive tape is adhered in the opening of the first annular frame;
A surface of the pressure-sensitive adhesive tape on which the groove portion of the second annular frame is formed is attached to an annular region between the inner edge of the first annular frame and the outer edge of the workpiece. A second annular frame attaching step;
A cutting tool insertion step of inserting a cutting tool into the groove portion in a non-contact state;
An adhesive tape cutting step of cutting the adhesive tape into a circular shape by relatively moving the cutting tool along the groove, and wherein the second annular frame is the annular frame according to claim 1. Characteristic work transfer method.

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