JP2005340859A - How to peel off the protective tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for peeling off a protective tape for peeling off a plurality of protective tapes affixed to the surface of a semiconductor wafer.
A protective tape T1 attached to a surface of a wafer W attracted and held on a chuck table by a tape attaching mechanism is cut into a wafer shape by a cutter unit. This process is repeated a plurality of times, and the protective tape is applied to the surface of the wafer W in multiple layers. Moreover, the protective tapes T1 and T3 attached in multiple are peeled one by one in order from the top by the peeling mechanism 20 of the tape peeling device 15.
[Selection] Figure 8

Description

  The present invention relates to a technique for peeling off a protective tape obtained by attaching a protective tape to a surface of a semiconductor wafer on which a pattern is formed.

  Conventionally, in the manufacturing process of a semiconductor wafer, the back surface of a semiconductor wafer (hereinafter simply referred to as “wafer”) is processed using a mechanical method such as a grinding method or a polishing method, or a chemical method using etching. The thickness is reduced. When a wafer is processed using these methods, a protective tape is affixed to the surface in order to protect the surface on which the wiring pattern is formed.

  That is, the wafer transferred to the back grinding process has its front surface (pattern surface) sucked and held by the chuck table and its back surface is ground by the grindstone. At this time, since stress due to grinding is applied to the surface of the wafer and the pattern may be damaged or soiled, a protective tape is attached to the surface.

In addition, wafers that have been thinned by grinding the back surface are easily damaged during processing and transport, and are inconvenient to handle due to bending and warping of the wafer, so two different types of protective tape are applied to the wafer surface. A protective tape that has been applied in advance to prevent wafer breakage and warping has also been proposed (see, for example, Patent Document 1).
JP 2000-331968 A

  However, the use of the two-layer protective tape described in JP 2000-331968 described above is beneficial in terms of reinforcing the wafer, but the following problems occur in the process of attaching and peeling the protective tape. There is.

  Normally, when affixing the protective tape to the wafer surface, it is rolled while pressing the adhering roller on the protective tape, and the protective tape is affixed to the wafer surface while the protective tape is stretched in the adhering direction of the protective tape. It has become.

  However, when a protective tape that has been bonded in advance as in the conventional example is applied to the wafer surface, the protective tape itself is more rigid than a single protective tape, so it is difficult to stretch the protective tape with the application roller. At this time, the stress may be applied to the wafer and the wafer may be damaged.

  In addition, when two layers of protective tape are peeled simultaneously, the two layers of protective tape are rich in rigidity, so the folding angle when the protective tape is folded and peeled is loosened, and as a result, the protective tape is strong against peeling. Requires tensile force. This strong pulling force may be applied to the thinly processed wafer and damage the wafer.

  Further, when the two-layer protective tape affixed to the wafer surface is cut along the periphery of the wafer, there is a disadvantage that it is difficult to cut due to the thickness and rigidity.

  The present invention has been made in view of such circumstances, and can reinforce the semiconductor wafer by imparting rigidity to the semiconductor wafer, and can be used to attach a protective tape to the semiconductor wafer or from the semiconductor wafer. It is a main object of the present invention to provide a method for attaching a protective tape and a method for removing the protective tape that can be easily peeled off.

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

  That is, the invention described in claim 1 is a method for peeling a plurality of protective tapes, which peels a plurality of protective tapes affixed on the surface of a semiconductor wafer on which a pattern is formed, and the protection of the plurality of sheets The tape is divided into a plurality of times and peeled one by one in order from the top.

  (Operation / Effect) According to the invention described in claim 1, by peeling a plurality of protective tapes stuck on the surface of the wafer on which the pattern is formed one by one in order from the top, The protective tape can be peeled off with a relatively small pulling force, which reduces the stress on the wafer. That is, it is possible to easily peel off the protective tape from the surface of the semiconductor wafer that has been thinly processed.

  The invention according to claim 2 is characterized in that, in the protective tape peeling method according to claim 1, the peeling directions of the plurality of protective tapes are changed according to the pattern surface. .

  (Operation / Effect) According to the invention described in claim 2, by changing the peeling direction along the concave portion of the pattern surface in accordance with the pattern surface, the efficiency can be improved without leaving the adhesive entering the concave portion of the pattern surface. It peels well.

  By peeling a plurality of protective tapes affixed onto the wafer surface on which the pattern is formed one by one in order from the top, the protective tapes can be peeled with a relatively small pulling force, This reduces stress on the wafer. That is, it is possible to easily peel off the protective tape from the surface of the semiconductor wafer that has been thinly processed.

<Reference example of how to apply protective tape>
First, the tape sticking apparatus of one Example used for the sticking method of the protective tape of a present Example is demonstrated with reference to drawings.
FIG. 1 is a front view showing a schematic configuration of a tape sticking apparatus, and FIGS. 2 to 4 are front views showing a tape sticking process.

  The semiconductor wafer protective tape attaching apparatus 1 according to the embodiment includes a tape supply unit 2 that supplies a protective tape T1 with a separator S, and a separator recovery unit 5 that peels and collects the separator S from the protective tape T1 with the separator S. The chuck table 7 for sucking and mounting the semiconductor wafer W (hereinafter simply referred to as “wafer W”), the tape attaching mechanism 8 for attaching the protective tape T1 while pressing the protective tape T1 on the wafer W, and the protection attached to the wafer W Equipped with a cutter unit 10 for cutting the tape T1 along the outer peripheral shape of the wafer W, a tape peeling mechanism 11 for peeling the remaining tape T2 after being cut, and a tape collecting unit 13 for collecting the peeled tape. Yes.

Hereinafter, the structure of each mechanism will be described in detail.
The tape supply unit 2 winds and guides the protective tape T1 with the separator S fed from the tape bobbin 3 around the guide roller group 4. The tape bobbin 3 is pivotally supported on a vertical wall (not shown) and is restricted from rotating via a brake mechanism or the like.

  The separator collection unit 5 has a collection bobbin 6 supported on a vertical wall (not shown) and is linked to a driving mechanism such as a motor.

  The chuck table 7 includes guide pins and the like. The chuck table 7 aligns with reference to the orientation flat of the transferred wafer W and holds the back surface by suction.

  The tape affixing mechanism 8 is held by a rail of the apparatus main body so that the frame can slide in the tape running direction, and is interlocked and connected via a drive unit such as a motor (not shown). An affixing roller 9 is rotatably supported by the frame, and the affixing roller 9 is driven to swing up and down by a cylinder (not shown). That is, the affixing roller 9 affixes the protective tape T1 to the surface of the wafer W while pressing and rolling the surface of the protective tape T1.

  The cutter unit 10 moves up and down over a standby position and a cutting action position for cutting out the protective tape T1 by an elevator mechanism (not shown), and cuts out the protective tape T1 along the periphery of the wafer W.

  The tape peeling mechanism 11 is gripped by a rail of the apparatus main body so that the frame can slide in the tape running direction, and is interlocked and connected via a drive unit such as a motor (not shown). A peeling roller 12 is rotatably supported on the frame, and the peeling roller 12 is driven to swing up and down by a cylinder (not shown). The peeling roller 12 is for peeling off the remaining tape T2 cut out along the outer peripheral edge of the wafer W from the wafer W.

The tape recovery unit 13 has a recovery bobbin 14 pivotally supported on a vertical wall (not shown), and is linked to a driving mechanism such as a motor. That is, a predetermined amount of the protective tape T1 is fed out from the tape supply unit 2 and supplied onto the wafer W, and the cut-out residual tape T2, which will be described later, is wound around the recovery bobbin 14 by operating the drive unit. It has become.

  Next, a method of applying the protective tape, which is a feature of this embodiment, to the surface of the wafer in multiple layers will be described with reference to the drawings using the tape applying apparatus having the above-described configuration. In this embodiment, a case will be described as an example where two tape applicators are used and two protective tapes of different types are applied to the wafer surface in multiple layers.

In addition, the plurality of types of protective tapes used in this example are, for example, an adhesive applied to a soft base material having a tensile modulus of elasticity of 30 to 100 MPa and a hard base material having a tensile modulus of elasticity of 100 to 1000 MPa. It has been done. The tensile modulus was measured by setting a sample of 1 cm ² at a tensile speed of 50 mm / min in an atmosphere at 23 ° C.

  First, the first and second tape applicators are arranged side by side, a soft protective tape T1 is set on the tape bobbin 3 of the first tape applicator, and the tape bobbin 3 of the other second tape applicator is hard. A protective tape T3 is set.

  Then, the wafer W is placed on the chuck table 7 of the first tape applicator, aligned, and held by suction. At this time, as shown in FIG. 1, the tape attaching mechanism 8 and the tape peeling mechanism 11 are located at the left initial position, and the cutter unit 10 is located at the upper standby position.

  When the alignment of the wafer W is completed, as shown in FIG. 2, the application roller 9 of the tape application mechanism 8 swings down, and the application roller 9 presses the protective tape T1 while holding the protective tape T1 in the tape running direction. Rolls in the opposite direction (from left to right in FIG. 2), and the protective tape T1 is evenly applied to the entire surface of the wafer W. When the tape sticking mechanism 8 reaches the end position, the sticking roller 9 is raised.

  Next, as shown in FIG. 3, the cutter unit 10 is lowered to the cutting action position, and the cutter unit 10 goes around the periphery of the wafer W, whereby the protective tape T <b> 1 is cut out along the wafer W.

  Then, after the cut-out of the protective tape T1, the cutter unit 10 rises and returns to the standby position as shown in FIG.

  Next, as shown in FIG. 4, the tape peeling mechanism 11 rolls up and peels the remaining tape T2 cut out on the wafer W while moving on the wafer W in the direction opposite to the tape running direction.

  When the tape peeling mechanism 11 reaches the end position of the peeling operation, the tape peeling mechanism 11 and the tape attaching mechanism 8 move in the tape running direction and return to the initial position shown in FIG. At this time, the remaining tape T2 is wound around the recovery bobbin 14, and a certain amount of the protective tape T1 is fed out from the tape supply unit 2. Thus, the operation of attaching the protective tape T1 to the surface of the wafer W in the first tape attaching apparatus is completed.

  The wafer W having the protective tape T1 attached to the surface by the first tape attaching device is transferred to the second tape attaching device. When the wafer W is placed on the chuck table 7 of the second tape attaching device, the attaching direction of the second protective tape T3 is rotated by 90 ° with respect to the attaching direction of the first protective tape T1. Adjust to paste from the shifted direction.

  Then, the same operation as the application of the first protective tape T1 is repeated, and the second protective tape T3 is superposed and attached onto the first protective tape T1. As a result, as shown in FIG. 5, a wafer W having two protective tapes T1 and T3 attached in multiple on the surface is formed.

  In addition, the combination of the protective tapes may be a soft tape and a hard tape, a hard tape and a soft tape, or the same type of tape in order from the surface of the wafer W to the upper side, or UV cured on the lower side. A plurality of ways are possible, such as a mold tape and a non-UV curable tape on the upper side. The number of protective tapes to be overlaid is not limited to two, and may be two or more.

  In the combination of the above-mentioned protective tapes, for example, when a combination of an ultraviolet curable type and a non-ultraviolet curable type tape is used, the ultraviolet curable tape is easily peeled off by performing the ultraviolet irradiation treatment on the protective tape. The pulling force applied to the wafer W during tape peeling is reduced.

  By repeatedly affixing a plurality of protective tapes individually on the surface of the wafer W by the method described above, when the affixing roller 9 rolls while pressing the surface of the protective tape, the protective tape acting in the tape affixing direction Stretching can be facilitated, and as a result, transient stress applied to the wafer by pressing / stretching when the protective tape is applied can be reduced.

  Further, by attaching the soft protective tape T1 to the surface of the wafer W, the unevenness formed on the surface of the wafer W is absorbed, and the surface can be kept flat. As a result, the protective tape T3 to be bonded onto the first protective tape T1 can be uniformly applied.

Further, the first protective tape T1 is attached by rotating the attaching direction of the second protective tape T3 by 90 ° with respect to the attaching direction of the first protective tape T1, and then attaching the first protective tape T1. The warpage of the wafer caused by the tape tension applied in the tape application direction when it is attached is corrected.

<Example>
<Protective tape peeling method>
First, the protective tape peeling apparatus of one Example used for the protective tape peeling method of a present Example is demonstrated with reference to drawings.
FIG. 6 is a front view showing a schematic configuration of the tape peeling device, and FIGS. 7 to 9 are explanatory views showing a process of peeling the protective tape.

  The semiconductor wafer protective tape peeling device 15 according to the embodiment includes a tape supply unit 16 that supplies a peeling tape Ts, and a wafer W (hereinafter simply referred to as “a”) supported by a ring-shaped frame f from the back surface via an adhesive tape Tn. A chuck table 19 for adsorbing and mounting the mounting frame F) and a protective tape T3 applied to the surface of the wafer W are affixed to the release tape Ts while being pressed together with the protective tape T3. And a tape collecting unit 22 for collecting both tapes peeled from the wafer W.

Hereinafter, the structure of each mechanism will be described in detail.
The tape supply unit 16 guides the peeling tape Ts fed from the tape bobbin 17 by the guide roller 18 and guides it to the peeling mechanism 20. The tape bobbin 17 is pivotally supported on a vertical wall (not shown).

  The chuck table 19 is provided with guide pins and the like, aligns the mounted mount frame F, and sucks and holds the back surface. Further, the chuck table 19 is gripped by a rail of the apparatus main body so that the frame can be slid in the traveling direction of the peeling tape Ts, and is interlocked and connected to a drive unit (not shown).

In the peeling mechanism 20, a peeling roller 21 is rotatably supported by the frame, and the peeling roller 21 is driven to swing up and down by a cylinder (not shown). That is, the release tape Ts is applied to the surface of the protective tape T3 while being pressed.

In the tape recovery unit 22, a recovery bobbin 23 is pivotally supported on a vertical wall (not shown), and the recovery bobbin 23 is linked to a drive unit such as a motor. In other words, a predetermined amount of the release tape Ts is fed out from the tape supply unit 16 and supplied onto the wafer W, and the release tape Ts integrated with the protective tape T3 is moved to the recovery bobbin 23 by operating the drive unit. It is designed to be wound up.

  Next, a method of peeling the protective tapes affixed to the surface of the wafer, which is a feature of this embodiment, will be described with reference to the drawings using the tape peeling apparatus having the above-described configuration.

  For example, as shown in FIG. 7, a mount in which a wafer W on which two protective tapes T1 and T3 having different hardness are attached to the front surface and a ring-shaped frame f are attached to each other from the back surface with an adhesive tape Tn. The frame F is placed on the chuck table 19. Then, alignment is performed and suction is held. At this time, the chuck table 19 moves to a position (left side in FIG. 7) where the peeling roller 21 contacts the peripheral edge of the wafer W, as shown in FIG.

  When the positioning of the mount frame F is completed, as shown in FIG. 8, the peeling roller 21 swings down and the chuck table 19 moves in the running direction of the peeling tape Ts. As the chuck table 19 moves, the peeling roller 21 rolls on the wafer W while pressing the peeling tape Ts. That is, the release tape Ts is attached on the protective tape T3 attached to the top, and the protective tape T3 attached with the release tape Ts is rolled up and peeled off together with the release tape Ts. .

  As shown in FIG. 9, when the chuck table 19 reaches the end position, the peeling roller 21 rises, and the chuck table 19 moves in the direction opposite to the tape running direction and returns to the initial position. At this time, the protective tape T3 that has been peeled off and integrated with the peeling tape Ts is wound around the recovery bobbin 23, and a certain amount of the peeling tape Ts is fed out from the tape supply unit 16. Thus, the peeling operation of the uppermost protective tape T3 affixed to the surface of the wafer W is completed.

  Next, it moves to the peeling operation of the protective tape T1. First, the direction of the mount frame F placed on the chuck table 19 is changed. For example, a method of rotating the mount frame F by 90 ° with respect to the peeling direction of the previously peeled protective tape T3 and shifting the position, or a protective tape along any of the orthogonal recesses formed on the pattern surface of the wafer W A method of changing the position of the mount frame F so as to peel off T1 is employed.

  Thus, if the peeling direction of the protective tape T1 directly attached to the surface of the wafer W is determined, the same operation as the peeling of the protective tape T2 is performed, and the protective tape T1 is peeled off from the surface of the wafer W.

In addition, since the back surface treatment is applied to the surface of each protective tape so that the tapes are not firmly bonded to each other when the tape is wound in a roll shape, it can be easily peeled one by one in order from the top It has become.

  By peeling the protective tapes affixed to the surface of the wafer W by the above-described method one by one in order from the top, the tapes can be peeled with a relatively small tensile force. That is, the stress on the wafer W due to the pulling force of the tape at the time of peeling is reduced.

  In addition, by removing the protective tape directly attached to the surface of the wafer W along the concave portion of the pattern, it is possible to avoid the adhesive remaining in the concave portion.

The present invention is not limited to the above embodiment, and can be modified as follows.
(1) In the above-mentioned method of attaching the protective tape, a roll-shaped protective tape is attached to the wafer W, and a plurality of pieces are attached while cutting along the periphery of the wafer W. You may make it stick.

(2) In the above method of applying the protective tape, two protective tape applying devices were used, but the type of protective tape was changed in units of lots using a single tape applying device and applied repeatedly. It may be.

(3) Although the chuck table 19 is moved in the tape running direction in the protective tape peeling method, the peeling mechanism 20 itself may be moved in the tape running direction.

(4) The method for peeling the protective tape has been described by taking mount peeling as an example. However, the method is not limited to this mounting peeling, and it is affixed to the surface of a wafer not supported by the mounting frame. The protective tape may be peeled off one by one.

It is a front view which shows schematic structure of the tape sticking apparatus which concerns on the sticking method of the protective tape of a reference example. It is a schematic front view explaining the tape sticking process of a reference example. It is a schematic front view explaining the tape sticking process of a reference example. It is a schematic front view explaining the tape sticking process of a reference example. It is a side view of the wafer where the protective tape was affixed to the reference example multiple times. It is a front view which shows schematic structure of the tape peeling apparatus which concerns on the peeling method of the protective tape which is an Example. It is a schematic front view explaining a tape peeling process. It is a schematic front view explaining a tape peeling process. It is a schematic front view explaining a tape peeling process.

Explanation of symbols

W ... Semiconductor wafer F ... Mount frame T1, T3 ... Protective tape Ts ... Peeling tape 1 ... Tape sticking device 2 ... Tape supply part 7 ... Chuck table 8 ... Tape sticking mechanism 10 ... Cutter unit 11 ... Tape peeling mechanism 13 ... Tape recovery Part 15 ... Tape peeling device 16 ... Tape supply part 19 ... Chuck table 20 ... Peeling mechanism 22 ... Tape recovery part

Claims (2)

A protective tape peeling method for peeling a plurality of protective tapes affixed multiple times on the surface of a semiconductor wafer on which a pattern is formed,
A method for peeling a protective tape, wherein the protective tape is divided into a plurality of times and peeled one by one in order from the top. In the peeling method of the protective tape of Claim 1,
The protective tape peeling method, wherein the peeling direction of the plurality of protective tapes is changed according to a pattern surface.

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