JP6375209B2 - Adhesive tape application method and adhesive tape application device - Google Patents

Description

  The present invention relates to a pressure-sensitive adhesive tape bonding method and a pressure-sensitive adhesive tape bonding method in which a pressure-sensitive adhesive tape is bonded to the back surface of a semiconductor wafer (hereinafter referred to as “wafer” as appropriate) and a ring frame. Relates to the device.

  In order to reinforce the wafer whose rigidity is lowered by the back surface grinding, only the central circuit forming portion is ground except the back surface outer periphery. That is, an annular convex portion is formed on the outer periphery of the back surface of the wafer. Prior to dicing the wafer, the wafer is mounted at the center of the ring frame via a supporting adhesive tape.

  For example, a wafer is placed and held on a holding table provided in a lower housing of a pair of upper and lower housings, and a ring frame is held on a frame holding table that surrounds the lower housing. After affixing the adhesive tape to the ring frame, the chamber is constructed by sandwiching the adhesive tape inside the ring frame between the two housings. At this time, since the adhesive tape and the back surface of the wafer are in close proximity to each other, a differential pressure is generated in the two spaces partitioned by the adhesive tape, and the hemispherical elastic body is adhered radially outward from the center of the adhesive tape. Press the tape and attach it to the back of the wafer.

  After the adhesive tape has been attached, the second pressing process is performed by blowing gas from the first pressing member to the adhesive tape that has been lifted up without being bonded at the inner corners of the annular protrusion (see Patent Document 1). ).

JP2013-232582A

  In the conventional adhesive tape application method, the adhesive tape is peeled off on the flat surface inside the annular convex portion after completion of the application even though the second application processing is performed on the inner corner of the annular convex portion, resulting in a gap. There is a problem such as. When the wafer in the peeled state is subjected to a dicing process, there is a problem that chips separated at a portion where the adhesive tape is not adhered are scattered and eventually broken.

  This invention is made in view of such a situation, Comprising: The adhesive tape sticking method and adhesive tape sticking which can stick an adhesive tape to the back surface of the semiconductor wafer in which the annular convex part was formed in the back surface periphery accurately The main purpose is to provide a device.

  Accordingly, the inventors diligently studied the cause of the peeling of the adhesive tape. As a result, the inventors obtained the following knowledge.

  When the appearance of the wafer with the adhesive tape peeled off was inspected, it was peeled off to the specific part where the ID or code for management was marked out of the entire circumference of the inner corner of the annular convex part standing up from the flat surface. Was concentrated. Further, when an appearance inspection of the wafer on which peeling occurred was performed, it was found that minute through holes were formed in the marking portion. That is, the through-hole was formed in the marking part engraved by the laser.

  Despite the use of a non-defective wafer with no through-holes in the marking area, repeated experiments in which pressure-sensitive adhesive tape was applied to the wafer using differential pressure in the chamber penetrated the marking area after application of the adhesive tape. Some of which holes were formed.

  When the adhesive tape is attached to the wafer in the chamber, the wafer is held in contact with the annular holding table from the opposite side only on the annular convex portion. Therefore, after applying the adhesive tape, in the pressurization process to return the chamber to the atmospheric state, pressure is applied to the marking part of the thinnest part engraved by the laser, and the through hole is formed. As a result, gas flows from the through hole. It was found that the adhesive tape was peeled off.

  Accordingly, the present invention has the following configuration in order to achieve such an object.

That is, an adhesive tape application method for attaching an adhesive tape for support across the back surface and the ring frame of the semiconductor wafer having an annular protrusion on the outer periphery of the back surface,
A holding process of abutting and holding the marking area inside the ring-shaped convex portion that is imprinted with characters, symbols, or a combination thereof, and the ring-shaped convex portion;
The adhesive tape between the ring frame and the semiconductor wafer is sandwiched between a pair of housings, a differential pressure is generated in the two spaces partitioned by the adhesive tape in the formed chamber, and the semiconductor is formed while the adhesive tape is recessed and curved. A pasting process to be pasted on the back side of the wafer;
It is provided with.

  (Operation / Effect) According to the above method, the marking region and the annular convex portion are held in contact with each other by the annular holding table. Therefore, since the marking area is covered with the holding table, pressurization by the inflowing gas does not act on the marking site in the process of increasing the pressure in the chamber. Accordingly, it is possible to avoid the formation of a through hole in the marked portion of the thinnest portion, thereby preventing the adhesive tape from peeling off.

  In the above method, the holding process may hold the semiconductor wafer on the holding table via an elastic sheet.

  According to this method, the degree of adhesion between the holding table and the marking area is increased by the elastic sheet. Accordingly, it is possible to more reliably prevent the stamped part from being damaged.

  Moreover, in the said method, you may affix on a semiconductor wafer, heating an adhesive tape in the affixing process.

  According to this method, the adhesive tape is softened by viscous heating, and the adhesive tape can be brought into close contact with the back surface of the wafer.

  The present invention has the following configuration in order to achieve such an object.

That is, an adhesive tape affixing device that affixes a supporting adhesive tape across the back surface and the ring frame of the semiconductor wafer having an annular protrusion on the outer periphery of the back surface,
An annular holding table that holds the annular convex portion in contact with the marking region inside the annular convex portion that is engraved with characters, symbols, or a combination thereof, and
A frame holding unit for holding a ring frame to which the adhesive tape is attached;
A chamber comprising a pair of housings for storing the holding table and sandwiching an adhesive tape attached to a ring frame;
A pasting mechanism including a control unit that creates a differential pressure in two spaces in the chamber partitioned by the adhesive tape, and affixes the adhesive tape to the back surface of the semiconductor wafer while being concavely curved.
It is provided with.

  (Operation / Effect) According to this configuration, the annular convex portion and the marking region can be held in contact with each other by the annular holding table. Therefore, pressurization by the gas flowing in during the pressurization in the chamber does not act on the marking area. Therefore, the above method can be suitably performed.

  In this configuration, it is preferable to provide an annular elastic sheet on the mounting surface of the holding table.

  According to this configuration, since the degree of adhesion with the holding table is increased, it is possible to more reliably prevent gas from flowing between the holding table and the wafer.

  According to the pressure-sensitive adhesive tape bonding method and the pressure-sensitive adhesive tape bonding apparatus of the present invention, a pressure-sensitive adhesive tape for supporting can be accurately bonded across the back surface and the ring frame of a semiconductor wafer having a reinforcing annular projection on the outer periphery of the back surface. .

It is a partially broken perspective view of a semiconductor wafer. It is a perspective view of the back surface side of a semiconductor wafer. It is a partial longitudinal cross-sectional view of a semiconductor wafer. It is a top view which shows the marking area | region of a semiconductor wafer. It is a front view which shows the whole structure of an adhesive tape sticking apparatus. It is a front view of the drive mechanism containing a chamber. It is a longitudinal cross-sectional view of a chamber. It is a top view of a holding table. It is a top view of a tape cutting mechanism. It is a schematic diagram which shows the sticking operation | movement of an adhesive tape. It is a schematic diagram which shows the sticking operation | movement of an adhesive tape. It is a schematic diagram which shows the sticking operation | movement of an adhesive tape. It is a schematic diagram which shows the sticking operation | movement of an adhesive tape. It is a schematic diagram which shows the sticking operation | movement of an adhesive tape. It is a perspective view of the mount frame which mounted the wafer.

  Embodiments of the present invention will be described below with reference to the drawings.

<Semiconductor wafer>
As shown in FIGS. 1 to 3, the semiconductor wafer W (hereinafter simply referred to as “wafer W”) is ground (back grinded) with the outer peripheral portion of the back surface leaving about 2 mm in the radial direction. In other words, a flat recess b is formed on the back surface and processed into a shape in which the annular protrusion r remains along the outer periphery thereof. For example, the processing is performed such that the depth d of the flat recess b is several hundred μm and the wafer thickness t in the grinding region is several tens μm. Accordingly, the annular protrusion r formed on the outer periphery of the back surface functions as an annular rib that increases the rigidity of the wafer W, and suppresses bending deformation of the wafer W during handling and other processing steps.

  On the outer periphery of the wafer W, a V-shaped notch N as an alignment mark is formed. Further, an ID for management is marked inside the notch N. The ID is a character, a symbol, or a combination of these, and is imprinted with a laser. Characters include alphabets and numbers. As shown in FIG. 4, the ID is engraved across the annular convex part r and the flat concave part b inside thereof. The ID part corresponds to the marking area of the present invention.

<Adhesive tape application device>
The top view of the adhesive tape sticking apparatus is shown by FIG.

  As shown in FIG. 5, the adhesive tape attaching device includes a tape supply unit 1, a separator collection unit 2, a tape attachment unit 3, a tape collection unit 4, and the like. Hereinafter, each configuration will be described in detail.

  The tape supply unit 1 is configured so that the separator S is peeled off by the peeling roller 5 in the process of supplying the adhesive tape T from the supply bobbin loaded with the original fabric roll around which the supporting adhesive tape T is wound to the attaching position. Has been. Note that the supply bobbin is coupled to an electromagnetic brake and applied with a suitable rotational resistance. Therefore, excessive feeding of the tape from the supply bobbin is prevented.

  Further, the tape supply unit 1 is configured to apply tension by pressing down the adhesive tape T downward by the dancer roller 8 at the tip end by swinging the swing arm 7 connected to the cylinder 6.

  The separator recovery unit 2 includes a recovery bobbin that winds up the separator S peeled off from the adhesive tape T. The recovery bobbin is rotationally driven in a forward and reverse direction by a motor.

  The tape applicator 3 is composed of a chamber 10, a tape applicator mechanism 11, a tape cutting mechanism 12, and the like. The chamber 10 corresponds to the pasting mechanism of the present invention.

  As shown in FIGS. 5 and 6, the chamber 10 includes a lower housing 10A and an upper housing 10B.

  The lower housing 10A is configured to reciprocate along the guide rail L between the lower side of the upper housing 10B configured to be movable up and down and the front side of the apparatus. Both housings 10A and 10B have an inner diameter smaller than the width of the adhesive tape T. The lower housing 10A has a rounded upper part of the cylinder and is subjected to a mold release process such as fluorine processing. The lower housing 10A includes a holding table 13 therein. The lower housing 11A includes a frame holding portion 22 that surrounds the lower housing 10A.

  The holding table 13 is a metal chuck table having a size equal to or larger than the shape of the wafer W, and is stored in the lower housing 10A. The chuck table 13 is connected in communication with an external vacuum device through a flow path. Further, as shown in FIGS. 7 and 8, the holding table 13 is formed with a holding portion 16 formed of an annular convex portion that abuts and supports the annular convex portion r of the wafer W from the back side. In addition, the holding unit 16 is provided with a holding region 18 that covers and holds the entire surface of the marking region 17 on which the ID of the wafer W is marked when the aligned wafer W is placed.

  An elastic sheet 19 having substantially the same shape is attached to the holding portion 16 and the holding region 18. The elastic sheet 19 has a through hole 20 at a position that coincides with the suction hole formed on the surface of the holding portion 16.

  A heater 21 is embedded inside the base of the holding table 13.

  The frame holding portion 22 is configured such that when the ring frame f is placed, the ring frame f and the cylindrical top portion of the lower housing 10A become flat.

  As shown in FIG. 6, the upper housing 10 </ b> B is provided in the elevating drive mechanism 24. The elevating drive mechanism 24 includes an elevating platform 27 that can move along a rail 26 that is vertically disposed on the back of the vertical wall 25, a movable frame 28 that is supported by the elevating platform 27 so that the height can be adjusted, An arm 29 extending forward from the frame 28 is provided. The upper housing 10 </ b> B is mounted on a support shaft 30 that extends downward from the tip of the arm 29.

  The elevator 27 is moved up and down by screwing the screw shaft 31 forward and backward by a motor 32.

  As shown in FIG. 7, both housings 10 </ b> A and 10 </ b> B are connected to a vacuum device 35 through a flow path 34. The flow path 34 on the upper housing 10B side is provided with an electromagnetic valve 36. A flow path 39 including electromagnetic valves 37 and 38 for opening to the atmosphere is connected to both housings 10A and 10B. Further, the upper housing 10B is connected to a flow path 41 having an electromagnetic valve 40 that adjusts the internal pressure once reduced by leakage. The opening / closing operation of the electromagnetic valves 36, 37, 38, 40 and the operation of the vacuum device 35 are performed by the control unit 70.

  Returning to FIG. 5, the tape sticking mechanism 11 moves horizontally along the guide rail 45 and the guide rail 45, which are installed on a pair of left and right support frames 44 erected on the apparatus base 43 with the holding table 13 interposed therebetween. And a nip roller 50 provided on the tape collecting unit 4 side. The adhering roller 49 is pivotally supported by a bracket connected to the tip of a cylinder provided in the movable table 46.

  The movable base 46 is supported by a belt 53 wound around a drive pulley 51 that is forward / reversely supported by a drive device fixedly arranged on the device base 43 and an idle pulley 52 that is supported on the support frame 44 side. Driven and transmitted, it is configured to move horizontally left and right along the guide rail 45.

  The nip roller 50 includes a feed roller 54 driven by a motor and a pinch roller 55 that moves up and down by a cylinder.

  As shown in FIG. 6, the tape cutting mechanism 12 is provided in a lift drive mechanism 24 that lifts and lowers the upper housing 10 </ b> B. That is, a boss portion 57 that rotates around the support shaft 30 via the bearing 56 is provided. As shown in FIG. 9, the boss portion 57 is provided with four support arms 58 to 61 extending radially from the center.

  A cutter bracket 63 that horizontally supports a disc-shaped cutter 62 is mounted at the tip of one support arm 58 so as to be movable up and down, and a pressure roller 64 is pivoted at the tip of the other support arms 59 to 61. It is mounted so as to be movable up and down via 65.

  A connecting portion 66 is provided at the upper portion of the boss portion 57, and the connecting portion 66 is drivingly connected to a rotating shaft of a motor 67 provided in the arm 29.

  As shown in FIG. 5, the tape recovery unit 4 includes a recovery bobbin that winds up the unnecessary adhesive tape T peeled off after cutting. The recovery bobbin is rotationally driven in a forward / reverse direction by a motor (not shown).

  Next, the operation of mounting the wafer W on the ring frame f through the adhesive tape T using the above-described embodiment apparatus will be described.

  The ring frame f is placed on the frame holding unit 22 by the transfer robot. The wafer W aligned by the transfer robot is placed on the holding table 13. At this time, the marking area 17 of the wafer W is held in contact with a holding area 18 projecting from the annular holding portion 16 of the holding table 13.

  When the holding table 13 sucks the wafer W and the frame holding part 22 sucks and holds the ring frame f, the lower housing 10A moves along the rail L toward the tape applying mechanism 12 side.

  As shown in FIG. 10, when the lower housing 10A reaches the tape application position of the tape application mechanism 12, the application roller 49 descends, and as shown in FIG. Adhesive tape T is applied over the top of housing 10A. A predetermined amount of adhesive tape T is fed out from the tape supply unit 1 while the separator S is peeled off in conjunction with the movement of the sticking roller 49.

  When the application of the adhesive tape T to the ring frame f is completed, the upper housing 10B is lowered as shown in FIG. Along with this lowering, the chamber 10 is configured by sandwiching the adhesive tape T with the adhesive surface exposed between the outer periphery of the wafer W and the inner diameter of the ring frame f between the upper housing 10B and the lower housing 10A. At this time, the adhesive tape T functions as a sealing material, and the upper housing 10B side and the lower housing 10B side are divided to form two spaces.

  The wafer W located in the lower housing 10A is in close proximity to the adhesive tape T with a predetermined clearance.

  The controller 70 operates the heater 21 to heat the adhesive tape T from the lower housing 10A side, and operates the vacuum device 35 with the electromagnetic valves 37, 38, and 40 shown in FIG. 7 closed to operate the upper housing. The inside of 10B and the inside of lower housing 10A are decompressed. At this time, the opening degree of the electromagnetic valve 36 is adjusted so that the pressure in the housings 10A and 10B is reduced at the same speed.

  When the insides of both housings 10A and 10B are depressurized to a predetermined pressure, the control unit 70 closes the electromagnetic valve 36 and stops the operation of the vacuum device 35.

  The control unit 70 gradually increases the inside of the upper housing 10B to a predetermined pressure while adjusting the opening of the electromagnetic valve 40 to leak. At this time, the air pressure in the lower housing 10A becomes lower than the air pressure in the upper housing 10B, and the pressure-sensitive adhesive tape T is drawn from the center to the lower housing 10A side by the differential pressure as shown in FIG. That is, the adhesive tape T is radially attached from the center of the wafer W to the outer periphery while being concavely curved. At this time, the air at the corners inside the annular protrusion r is evacuated, and the adhesive tape T is bonded in a state where the gap is crushed.

  When the inside of the upper housing 10B reaches a preset atmospheric pressure, the control unit 70 adjusts the opening degree of the electromagnetic valve 38 so that the atmospheric pressure in the lower housing 10A is the same as the atmospheric pressure in the upper housing 10B. Thereafter, as shown in FIG. 14, the control unit 70 raises the upper housing 10B to release the atmosphere in the upper housing 10B, and fully opens the electromagnetic valve 38 to open the lower housing 11A.

  The tape cutting mechanism 12 operates while the adhesive tape T is stuck on the wafer W in the chamber 10. At this time, as shown in FIGS. 12 and 13, the cutter 62 cuts the adhesive tape T affixed to the ring frame f into the shape of the ring frame f, and the pressing roller 64 follows the cutter 62 to follow the ring frame. Press while rolling the tape cutting part on f. That is, when the upper housing 10B is lowered and the chamber 10 is constituted by the lower housing 10A, as shown in FIG. 5, the cutter 62 and the pressing roller 64 of the tape cutting mechanism 12 have also reached the cutting action position.

  Since the adhesive tape T has been attached to the wafer W and the adhesive tape T has been cut when the upper housing 10B is raised, the pinch roller 55 is lowered and then cut toward the tape collecting unit 4 The unnecessary adhesive tape T is wound up and collected, and a predetermined amount of the adhesive tape T is fed out from the tape supply unit 1.

  When the peeling of the adhesive tape T is completed and the nip roller 55 and the affixing roller 49 are returned to the initial positions, the lower housing holds the mount frame MF shown in FIG. 15 with the adhesive tape T bonded to the ring frame f and the back surface. 10A moves to the unloading position in front of the apparatus.

  This completes one round of operation of attaching the adhesive tape T to the ring frame f and the back surface of the wafer W. Thereafter, the above process is repeated until the mount frame MF reaches a predetermined number.

  According to the apparatus of this embodiment, the marking region 17 in which the ID of the wafer W is imprinted is brought into contact with the marking region 17 by bringing the holding region 18 projecting inwardly from the holding portion of the annular projection of the holding table 13 into the annular projection. Only the suction region is sealed, so that the marking region 17 is sealed. Therefore, in the process of releasing the pressure reduction in the chamber 10 and releasing the chamber 10 to increase the pressure, even if air flows into the space between the holding table body partitioned by the wafer W and the wafer W, the gas flows into the marking portion. There is no. That is, since pressurization due to inflow of gas does not act on the stamped portion, formation of a through hole due to breakage can be prevented, and as a result, peeling of the adhesive tape T can be prevented.

  The present invention can also be implemented in the following forms.

  (1) In the above-described embodiment device, a heater may be embedded in the upper housing 11B, and the adhesive tape T may be heated from above and below.

  (2) In the above-described embodiment apparatus, after the adhesive tape T is previously attached to the ring frame in different steps, the adhesive tape T is placed on the frame holding portion 22 of the above-described embodiment apparatus and attached to the back surface of the wafer W. May be.

DESCRIPTION OF SYMBOLS 1 ... Tape supply part 2 ... Separator collection | recovery part 3 ... Tape sticking part 4 ... Tape collection | recovery part 10 ... Chamber 10A ... Lower housing 10B ... Upper housing 11 ... Tape sticking mechanism 12 ... Tape cutting mechanism 13 ... Holding table 15 ... Vacuum apparatus 16 ... Holding part 17 ... Marking area 18 ... Holding area 19 ... Elastic sheet 22 ... Frame holding part 70 ... Control part W ... Semiconductor wafer f ... Ring frame T ... Adhesive tape

Claims (6)

An adhesive tape application method for attaching an adhesive tape for support over the back surface and the ring frame of a semiconductor wafer having an annular protrusion on the outer periphery of the back surface,
A holding process of abutting and holding the marking area inside the ring-shaped convex portion that is imprinted with characters, symbols, or a combination thereof, and the ring-shaped convex portion;
The adhesive tape between the ring frame and the semiconductor wafer is sandwiched between a pair of housings, a differential pressure is generated in the two spaces partitioned by the adhesive tape in the formed chamber, and the semiconductor is formed while the adhesive tape is recessed and curved. A pasting process to be pasted on the back side of the wafer;
A method of applying an adhesive tape, comprising: In the adhesive tape sticking method of Claim 1,
In the holding process, the semiconductor wafer is held on a holding table via an elastic sheet. In the adhesive tape sticking method according to claim 1 or 2,
The said affixing process affixes on a semiconductor wafer, heating an adhesive tape, The adhesive tape affixing method characterized by the above-mentioned. An adhesive tape affixing device that affixes a supporting adhesive tape across the back surface and ring frame of a semiconductor wafer having an annular convex portion on the outer periphery of the back surface,
An annular holding table that holds the annular convex portion in contact with the marking region inside the annular convex portion that is engraved with characters, symbols, or a combination thereof, and
A frame holding unit for holding a ring frame to which the adhesive tape is attached;
A chamber comprising a pair of housings for storing the holding table and sandwiching an adhesive tape attached to a ring frame;
A pasting mechanism including a control unit that creates a differential pressure in two spaces in the chamber partitioned by the adhesive tape, and affixes the adhesive tape to the back surface of the semiconductor wafer while being concavely curved.
An adhesive tape affixing device characterized by comprising: In the adhesive tape sticking device according to claim 4,
The pressure-sensitive adhesive tape attaching apparatus, wherein an elastic sheet is provided on the mounting surface of the holding table. In the adhesive tape sticking device according to claim 4 or 5,
A pressure-sensitive adhesive tape applying apparatus comprising a heater for heating the pressure-sensitive adhesive tape in the process of applying the pressure-sensitive adhesive tape to the semiconductor wafer.

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