JP2019175927A - Wafer dividing apparatus and method - Google Patents

Abstract

To provide a wafer dividing apparatus and method, capable of preventing a decrease in tension of a dicing tape when dividing a wafer.SOLUTION: A wafer dividing apparatus 10 includes: a wafer on which a to-be-divided line is formed; expanding portions (18, 30) for expanding a dicing tape to which a frame surrounding the wafer is attached; a tension adjusting unit 15 for adjusting a tension applied to the dicing tape in accordance with a decrease in the tension of the dicing tape.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wafer dividing apparatus and method, and more particularly to a technique for dividing a wafer (semiconductor wafer) in which a plurality of chips are integrally formed into chips.

  In the process of manufacturing chips such as semiconductor elements, a wafer in which a plurality of chips are integrally formed is created, a dicing tape is attached to the back surface of the wafer, and the wafer is divided into chips. .

  Patent Document 1 discloses a wafer dividing jig for dividing a wafer attached to the surface of a sheet (dicing tape) along a plurality of planned cutting lines.

  In Patent Document 1, in a state where a dicing tape to which a wafer is attached is expanded, a portion of the wafer to be cut is locally vacuum-sucked through the dicing tape. As a result, a tensile stress due to the expansion of the dicing tape acts first on the planned cutting line of the wafer, and then a bending stress due to vacuum suction acts. Finally, bending stress due to the pushing up of the edge of the wafer dividing jig acts on the planned cutting line of the wafer. As a result, the wafer is cut along the planned cutting line.

  In Patent Literature 1, the wafer is divided into a plurality of chips by moving (scanning) the wafer dividing jig and repeatedly dividing the plurality of cutting planned lines one by one.

JP 2006-344910 A

  In Patent Document 1, when the wafer division jig is scanned and the wafer is cleaved, the area where the chip interval is widened increases. As the area where the chip interval is widened increases, the tension of the dicing tape along the scanning direction of the wafer dividing jig decreases. The following problems occur due to the decrease in the tension of the dicing tape.

  First, stick slip (vibration) occurs between the dicing tape and the wafer dividing jig. Due to this stick slip, the cleaved adjacent chips may come into contact with each other, causing damage to the chips.

  Secondly, there is a problem that the dicing tape is easily bent. In the case of a substantially circular wafer, the closer to the center of the wafer parallel to the scanning direction of the wafer dividing jig, the longer the dicing tape becomes, so the deflection of the dicing tape increases. For this reason, straight deviation (for example, deviation in a direction substantially perpendicular to the dicing tape) occurs between the dicing tape and the wafer dividing jig. Due to this straight misalignment, the dicing tape on the front side of the wafer dividing jig is compressed and the chips are rubbed with each other, so that the wafer dividing quality may be deteriorated or the tape may be broken.

  Third, when the amplitude of the stick slip increases, the dicing tape may be peeled off from the wafer dividing jig.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wafer dividing apparatus and method capable of preventing a decrease in tension of a dicing tape during wafer division.

  In order to solve the above-described problem, a wafer dividing apparatus according to the first aspect of the present invention includes an expanding unit that expands a dicing tape to which a wafer on which a dividing line is to be formed and a frame that surrounds the wafer is attached. A tension adjusting unit that adjusts a tension applied to the dicing tape in accordance with a decrease in the tension of the dicing tape.

  According to the first aspect, it is possible to prevent the occurrence of stick slip and bending due to the decrease in the tension of the dicing tape by determining the decrease in the tension of the dicing tape and adjusting the tension of the dicing tape. .

  In the wafer dividing apparatus according to the second aspect of the present invention, in the first aspect, the expanding unit includes an expanding ring and a holding unit that holds the frame, and the expanding ring and the frame are relatively moved. The dicing tape is expanded.

  In the wafer dividing apparatus according to the third aspect of the present invention, in the first or second aspect, the tension adjusting unit includes an air cylinder or a hydraulic cylinder for applying a constant force to the expanding ring or the frame. Prepare.

  The wafer dividing apparatus according to the fourth aspect of the present invention is the first or second aspect, wherein the detection unit for detecting a change in the tension of the dicing tape, the drive for relatively moving the expanding ring and the frame. The tension adjusting unit adjusts the tension applied to the dicing tape by controlling the drive unit when it is determined that the tension of the dicing tape has decreased based on the detection result of the detecting unit. It is.

  The wafer dividing apparatus according to a fifth aspect of the present invention is the wafer dividing apparatus according to the fourth aspect, wherein the driving unit includes a motor for relatively moving the expanding ring and the frame, and the detecting unit applies a load applied to the motor. The tension adjusting unit measures and determines whether or not the tension of the dicing tape has decreased based on the load applied to the motor measured by the detecting unit.

  According to the 5th aspect, it becomes possible to determine the fall of the tension | tensile_strength of a dicing tape based on the load concerning an expanded part.

  In the wafer dividing apparatus according to the sixth aspect of the present invention, in the fourth or fifth aspect, the detection unit includes a displacement meter for measuring the displacement of the dicing tape, and the tension adjustment unit is measured by the displacement meter. Based on the displacement of the dicing tape, it is determined whether or not the tension of the dicing tape has decreased.

  The wafer dividing apparatus according to a seventh aspect of the present invention is the wafer dividing apparatus according to any one of the fourth to sixth aspects, wherein the detection unit includes a transmittance measuring unit for measuring the light transmittance of the dicing tape, The adjusting unit is configured to determine whether or not the tension of the dicing tape has decreased based on the displacement of the dicing tape measured by the transmittance measuring unit.

  According to the sixth and seventh aspects, it is possible to determine a decrease in the tension of the dicing tape by detecting the deflection and stick slip generated by the change in the tension of the dicing tape.

  The wafer dividing apparatus according to the eighth aspect of the present invention is the wafer dividing apparatus according to any one of the fourth to seventh aspects, wherein the wafer is in contact with the surface on which the dicing tape is attached, and the wafer dividing line is formed. And a wafer dividing jig for applying a bending stress to the substrate.

  A wafer dividing apparatus according to a ninth aspect of the present invention further includes a jig driving motor for scanning the wafer dividing jig in the eighth aspect, and the detection unit is a load applied to the jig driving motor. The tension adjusting unit determines whether or not the tension of the dicing tape has decreased based on the load applied to the jig driving motor measured by the detecting unit.

  According to the ninth aspect, it is possible to determine the decrease in the tension of the dicing tape by detecting the bending and stick slip caused by the change in the tension of the dicing tape by detecting the load applied to the jig. become.

  A wafer dividing apparatus according to a tenth aspect of the present invention is the vacuum dividing apparatus according to the eighth or ninth aspect, wherein the wafer abutting surface of the wafer dividing jig that is in contact with the surface to which the dicing tape is attached is vacuum-sucked through a suction port. A vacuum source is further provided.

  A wafer dividing apparatus according to an eleventh aspect of the present invention is the wafer dividing apparatus according to the tenth aspect, wherein the detection unit includes a pressure sensor that measures the pressure in the pipe from the suction port to the vacuum source, and the tension adjustment unit is the pressure sensor. Whether or not the tension of the dicing tape has decreased is determined based on the pressure in the pipe measured by the above.

  According to the eleventh aspect, it is possible to determine a decrease in the tension of the dicing tape based on a change in pressure when an air leak path is formed due to the slack caused by the decrease in the tension of the dicing tape. become.

  In the wafer dividing method according to the twelfth aspect of the present invention, the expanding step of expanding the dicing tape to which the wafer on which the dividing line is to be formed and the frame surrounding the wafer are attached is applied, and the tension of the dicing tape is reduced. And a tension adjusting step for adjusting the tension applied to the dicing tape accordingly.

  According to the present invention, it is possible to prevent a decrease in the tension of the dicing tape, and thus it is possible to prevent the occurrence of stick slip and deflection due to the decrease in the tension of the dicing tape.

FIG. 1 is a block diagram showing a wafer dividing apparatus according to the first embodiment of the present invention. FIG. 2 is a perspective view showing the wafer. FIG. 3 is an enlarged perspective view showing the wafer dividing jig. FIG. 4 is an enlarged cross-sectional view of the wafer dividing jig. FIG. 5 is a flowchart showing the wafer dividing method according to the first embodiment of the present invention. FIG. 6 is a block diagram showing a wafer dividing apparatus according to the second embodiment of the present invention. FIG. 7 is a flowchart showing a wafer dividing method according to the second embodiment of the present invention. FIG. 8 is a flowchart showing a tape tension determining step in the wafer dividing method according to the second embodiment of the present invention. FIG. 9 is a block diagram showing a wafer dividing apparatus according to the third embodiment of the present invention. FIG. 10 is a flowchart showing a tape tension determining step in the wafer dividing method according to the third embodiment of the present invention. FIG. 11 is a block diagram showing a wafer dividing apparatus according to the fourth embodiment of the present invention. FIG. 12 is a graph showing an example of displacement of the dicing tape when tension adjustment of the dicing tape is not performed. FIG. 13 is a graph showing the change over time of the displacement of the dicing tape when the tension of the dicing tape is adjusted. FIG. 14 is a flowchart showing a tape tension determining step in the wafer dividing method according to the fourth embodiment of the present invention. FIG. 15 is a block diagram showing a wafer dividing apparatus according to the fifth embodiment of the present invention. FIG. 16 is a graph showing an example of the transmittance of the dicing tape when the tension of the dicing tape is not adjusted. FIG. 17 is a graph showing the change with time of the transmittance of the dicing tape when the tension of the dicing tape is adjusted. FIG. 18 is a flowchart showing a tape tension determination step in the wafer dividing method according to the fifth embodiment of the present invention. FIG. 19 is a block diagram showing a wafer dividing apparatus according to the sixth embodiment of the present invention. FIG. 20 is a flowchart showing a tape tension determination step in the wafer dividing method according to the sixth embodiment of the present invention.

  Embodiments of a wafer dividing apparatus and method according to the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
(Wafer splitting device)
FIG. 1 is a block diagram showing a wafer dividing apparatus according to the first embodiment of the present invention. In the following description, a three-dimensional orthogonal coordinate system in which a plane substantially parallel to the wafer W is an XY plane is used.

  The wafer dividing apparatus 10 according to the present embodiment is configured so that a pushing ring (expanding ring) 30 and the holding unit 18 of the wafer W are relatively moved, and a dicing tape (hereinafter, referred to as “a dicing tape” attached to the back surface of the wafer W). (It is also referred to as a tape.) An apparatus for dividing the wafer W into individual chips C along the line L (see FIG. 2) by dividing (expanding) S.

  As shown in FIG. 1, the wafer dividing apparatus 10 according to the present embodiment includes a control unit 12 including a processor, a memory, and an input device for controlling the operation of each unit of the wafer dividing apparatus 10. The control unit 12 controls the operation of each unit of the wafer dividing apparatus 10 including the detection unit 14, the jig driving motor 34, and the vacuum source 36 based on an input from a user or a predetermined program.

  The wafer W is made of silicon and has a substantially disk shape, and the diameter of the wafer W is 300 mm as an example. A dicing tape S to which an adhesive for die bonding (for example, a die attach film (DAF)) is applied is attached to the back surface of the wafer W. The wafer W is divided into a plurality of sections by a grid-like dividing line L, and a semiconductor device is formed in each section. In addition, a division starting point is formed on the wafer W along the division line L. The division starting point of the wafer W may be a cut formed on the surface of the wafer W using a blade, or may be a modified layer formed inside the wafer W by irradiating a laser.

  The frame F is a substantially annular member having rigidity, and the inner diameter of the frame F strokes the wafer dividing jig 32 (see FIGS. 3 and 4) on the back side of the wafer W with the dicing tape S expanded. The size is 506 mm as an example. The dicing tape S is attached to the frame F, and the wafer W is attached to the dicing tape S inside the substantially annular frame F. In the following description, a work unit in which a wafer W as a work is attached to a frame F via a dicing tape S is described as a work unit.

  In this embodiment, by expanding the dicing tape S, a tensile stress is applied to the planned cutting line L formed on the wafer W, and a bending stress is applied to the planned cutting line L by the wafer dividing jig 32. The wafer W is divided into chips. In this embodiment, a change in the tension of the dicing tape S is detected, and the tension of the dicing tape S is controlled according to the change in tension.

(Configuration for applying tensile stress to the wafer)
First, a configuration for expanding the dicing tape S and applying a tensile stress to the division line L of the wafer W will be described.

  The work unit is placed on the push-up ring 30 so that the back surface of the surface to which the wafer W is attached is on the push-up ring 30 side.

  The push-up ring 30 is a substantially cylindrical member, and the diameter (outer diameter) of the push-up ring 30 is smaller than the diameter of the frame F. The inner diameter of the push-up ring 30 may be larger than the diameter of the wafer W. The work unit is attached to the push-up ring 30 such that the upper end portion (+ Z side end portion) of the push-up ring 30 contacts the gap portion between the wafer W and the frame F adhered to the dicing tape S. Placed.

  The holding unit 18 includes a fixing member for holding (fixing) the frame F placed on the push-up ring 30. As the holding part 18, for example, a structure in which a plurality of clamp mechanisms for fixing the frame F are arranged along the circumferential direction of the substantially annular frame F can be used.

  The wafer dividing apparatus 10 includes a tension adjusting mechanism 15 (tension adjusting unit) that keeps the tension of the dicing tape S constant by pressing the holding unit 18 in the −Z-axis direction. As the tension adjusting mechanism 15, for example, an air cylinder or a hydraulic cylinder (hereinafter referred to as a hydraulic cylinder) can be employed. There may be one or more air cylinders or hydraulic cylinders. An air cylinder or a hydraulic cylinder may be provided for each clamp mechanism of the holding unit 18.

  When the holding unit 18 moves in the −Z-axis direction with the frame F fixed, the dicing tape S is expanded. As a result, a tensile stress acts on the division line L formed on the wafer W.

  Then, when the value of the tension applied to the dicing tape S is a predetermined value (T), the tension applied to the dicing tape S when the sliding position of the air cylinder or the hydraulic cylinder as the tension adjusting mechanism 15 is an intermediate position. The pressure applied to the air cylinder or hydraulic cylinder is adjusted so that (T) and the thrust (F) of the air cylinder or hydraulic cylinder are balanced (T = F). Here, the intermediate position of the air cylinder or hydraulic cylinder refers to a position that is not the stroke end of the air cylinder or hydraulic cylinder. When the tension (T) of the dicing tape S decreases (T <F), the thrust (F) of the air cylinder or the hydraulic cylinder is constant, so that the tension (T) and the thrust (F) are balanced at the sliding position ( Move to T = F) position. The tension of the dicing tape S is kept constant by a feedback mechanism using this air cylinder or hydraulic cylinder.

  In the present embodiment, the expanding ring 30 and the frame F are relatively moved in the Z-axis direction, but the present invention is not limited to this. For example, a configuration in which the table on which the workpiece is placed and the frame F are relatively moved is also applicable to this embodiment.

(Configuration for applying bending stress to the wafer)
Next, a configuration for applying a bending stress to the division line L by the wafer dividing jig 32 will be described.

  The wafer dividing jig 32 is a columnar (quadrangular columnar) member, and is arranged so as to be substantially parallel to the wafer W. The dimension of the wafer dividing jig 32 in the X direction is 20 mm as an example, and the dimension in the Y direction is 320 mm as an example.

  As shown in FIGS. 3 and 4, a flat surface portion 32 </ b> A <b> 1 and a concave portion 32 </ b> A <b> 2 are formed on the upper contact surface 32 </ b> A of the wafer dividing jig 32 in order from the front side in the scanning direction of the wafer dividing jig 32. Has been. Each of the flat surface portion 32A1 and the concave portion 32A2 is a rectangular region extending in the length direction of the wafer dividing jig 32. The recess 32A2 is a recessed region extending in the length direction of the wafer dividing jig 32. The flat portion 32A1 is made of stainless steel, and the recess 32A2 is made of an aluminum alloy. A coating for improving the slipperiness of the dicing tape S is applied to the surfaces of the flat portion 32A1 and the recess 32A2 that are in contact with the dicing tape S. For this coating, polytetrafluoroethylene (Teflon (registered trademark)) or Tafram (registered trademark) can be used.

  A suction port 32B is formed on a line segment at the boundary between the flat surface portion 32A1 and the concave portion 32A2 of the contact surface 32A. A plurality of suction ports 32B may be arranged at a predetermined interval (for example, several mm) along the length direction of the wafer dividing jig 32 (Y-axis direction in FIG. 1 and the like). The suction port 32B is connected to the vacuum source 36 via a pipe 38 extending from the suction port 32B to the vacuum source 36. When the line segment in which the suction port 32B is formed is aligned with the position of the division planned line L of the wafer W and suction is started from the suction port 32B, the dicing tape S is deformed following the recess 32A2. As a result, the wafer W is divided into chips C.

  In FIG. 3, a vacuum pump is shown as an example of the vacuum source 36, but the type of the vacuum source is not limited to this. For example, a vacuum generator other than a vacuum pump (for example, an ejector, Convum (registered trademark), etc.) may be used as the vacuum source 36. Further, the wafer dividing apparatus 10 according to this embodiment may not include a vacuum source. For example, the pipe 38 can be connected to a vacuum generator provided in a factory where the wafer dividing apparatus 10 is installed. Also good.

  When bending stress is applied to the planned dividing line L, the wafer dividing jig 32 is scanned and moved to a position overlapping with the planned dividing line L of the wafer W, and the vacuum source 36 is used to suck from the suction port 32B of the wafer dividing jig 32. Perform vacuum suction. Then, the dicing tape S is attracted to the upper end portion of the wafer dividing jig 32, and the upper end portion of the wafer dividing jig 32 comes into contact with the position of the division line L of the wafer W. Thereby, a bending stress is applied to the wafer W, and the wafer W can be cleaved along the division line L.

  In the following description, for convenience of explanation, the wafer dividing jig 32 is arranged so that the upper end portion thereof is parallel to the Y axis, and the division lines L of the wafer W are arranged in the X axis direction and the Y axis direction. Suppose that they are parallel grids.

  The wafer dividing jig 32 can be moved (scanned) in the XY-axis direction by a jig driving motor 34 and can be rotated about the Z-axis. By scanning the wafer dividing jig 32 along the X-axis direction and sequentially applying a bending stress to the planned cutting line L (Y-scheduling line) parallel to the Y-axis, the wafer W along the Y-scheduled line is obtained. Cleave. Next, after the cleaving of the wafer W along the Y division planned line is completed, the wafer dividing jig 32 is rotated by 90 ° around the Z axis. Then, the wafer dividing jig 32 is scanned along the Y-axis direction, and a bending stress is applied to the planned dividing line L (X-scheduled line) parallel to the X-axis, thereby causing the X-scheduled line along the X-scheduled line. The wafer W is cleaved. Thus, the wafer W is divided for each chip C.

  The wafer dividing jig 32 may be movable in the Z-axis direction so that the position of the wafer dividing jig 32 in the Z-axis direction can be adjusted.

(Configuration related to dicing tape tension control)
Next, a configuration related to control of the tension of the dicing tape will be described.

  As described above, the tension adjusting mechanism 15 according to the present embodiment includes an air cylinder or a hydraulic cylinder. In this embodiment, the driving pressure of the air cylinder or hydraulic cylinder of the tension adjusting mechanism 15 is kept constant, and the tension of the dicing tape S and the driving force of the air cylinder or hydraulic cylinder are balanced at an intermediate position of the air cylinder or hydraulic cylinder. State. Thereby, the relative movement of the push-up ring 30 and the frame F is mechanically performed so that the tension of the dicing tape S is constant.

(Wafer splitting method)
FIG. 5 is a flowchart showing the wafer dividing method according to the first embodiment of the present invention.

  As shown in FIG. 5, first, when the division of the wafer W is started, the push-up ring 30 and the frame F are relatively moved, and the dicing tape S is expanded (Step S1: Expanding process).

  Next, when the value of the tension applied to the dicing tape S is a predetermined value (T), the sliding position of the air cylinder or the hydraulic cylinder as the tension adjusting mechanism 15 is applied to the dicing tape S at the intermediate position. The pressure applied to the air cylinder or hydraulic cylinder is adjusted so that the tension (T) and the thrust (F) of the air cylinder or hydraulic cylinder are balanced (T = F) (step S2). In step S2, for example, the air cylinder or the hydraulic cylinder may be manually adjusted while measuring the tension of the dicing tape S using a tension measuring device. In step S2, an actuator for driving the holding portion 18 is prepared, the tension of the dicing tape S is obtained based on the load applied to the actuator, and when the tension of the dicing tape S is a predetermined value, You may adjust so that the sliding position of the air cylinder or hydraulic cylinder as the adjustment mechanism 15 may become an intermediate position.

  Next, the wafer dividing jig 32 sequentially moves to the position of each division planned line L, and the wafer W is divided for each division planned line L. If the tension (T) of the dicing tape S decreases during the wafer W division operation (T <F), the sliding position of the air cylinder or hydraulic cylinder of the tension adjusting mechanism 15 is balanced with the tension of the dicing tape S. A feedback operation is performed so as to move to the (T = F) position (step S3: tension adjusting step).

  When the division of the wafer W is finished for all the division lines L (Yes in step S4), the process is finished.

  According to the present embodiment, by using an air cylinder or a hydraulic cylinder as the tension adjusting mechanism 15, it is possible to prevent a decrease in the tension of the dicing tape S during the operation of dividing the wafer W.

(Modification)
In this embodiment, the frame F having rigidity is used, but a dicing frame having low rigidity can also be used. In this case, a plurality of air cylinders or hydraulic cylinders are arranged in the circumferential direction of the dicing frame. In this case, the dicing frame is deformed according to the relationship between the tension for each part or direction of the dicing tape S and the force applied to the dicing frame by the air cylinder or the hydraulic cylinder. Due to the deformation of the dicing frame, even if there is a tension imbalance in each direction of the dicing tape S, it is possible to maintain a balance of forces. In this case, for example, the residual stress of the dicing tape S is different between the MD direction (Machine direction: the direction in which the dicing tape S is applied) and the TD (Transverse direction) perpendicular to the MD direction. However, the tension of the dicing tape S can be kept constant.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

(Wafer splitting device)
FIG. 6 is a block diagram showing a wafer dividing apparatus according to the second embodiment of the present invention.

  As shown in FIG. 6, the wafer dividing apparatus 10 </ b> A according to the present embodiment includes a detection unit 14 and a drive unit 16.

  The drive unit 16 includes a motor (for example, a servomotor) used as a drive actuator for relative movement between the push-up ring 30 and the frame F. Further, the drive unit 16 is a mechanism driven by the motor (for example, a mechanism for driving the holding unit 18 in the Z-axis direction using a ball screw, a rack and pinion mechanism, or a holding unit 18 using a gear or a belt. In the Z-axis direction). As a result, the push-up ring 30 and the frame F can be moved relative to each other.

  The detection unit 14 measures a load (for example, voltage value, torque) applied to the motor of the drive unit 16. The control unit 12 (tension adjusting unit) changes the power supplied to the motor of the drive unit 16 according to the measured value (detection result) of the load of the motor. Here, the relationship between the power supplied to the motor and the drive amount of the drive unit 16 can be determined experimentally. Thereby, the balance between the tension of the dicing tape S and the force applied to the frame F by the air cylinder or the hydraulic cylinder can be adjusted.

(Wafer splitting method)
FIG. 7 is a flowchart showing a wafer dividing method according to the second embodiment of the present invention, and FIG. 8 is a flowchart showing a tape tension determining step in the wafer dividing method according to the second embodiment of the present invention. is there.

  As shown in FIG. 7, first, when the division of the wafer W is started (step S10: expanding process), the control unit 12 determines the tension of the dicing tape S (step S12).

  As shown in FIG. 8, in the tension determination step (step S <b> 12 in FIG. 7), first, the detection unit 14 measures the load on the motor in the drive unit 16 (step S <b> 120). And the control part 12 acquires the measured value of the load by the detection part 14, and if there is no fluctuation | variation of a load (No of step S122), it will determine with the tension | tensile_strength reduction of the dicing tape S not having (step S124). On the other hand, if there is a load variation (Yes in step S122), the control unit 12 determines that the tension of the dicing tape S has decreased (step S126).

  In step S122, for example, when the difference absolute value between the measured value of the load and the immediately preceding measured value is greater than or equal to the threshold value, the control unit 12 may determine that there is a load variation. In addition, when the difference absolute value between the measured value of the load and the representative value (for example, an average value) of the measured values for the predetermined number of times immediately before is greater than or equal to the threshold value, the control unit 12 determines that there is a load variation. You may do it. Further, when the maximum value of the absolute difference between the measured value of the load and the measured value for the predetermined number of times immediately before is greater than or equal to the threshold value, the control unit 12 may determine that there is a change in the load. In addition, the determination method of the presence or absence of a fluctuation | variation is not limited to this.

  If it is determined that the tension of the dicing tape S has not decreased (No in step S14), the process returns to step S12, and the control unit 12 continues to monitor the variation in the tension of the dicing tape S.

  On the other hand, if it is determined that the tension of the dicing tape S is reduced (Yes in step S14), the control unit 12 controls the drive unit 16 to change the amount of power supplied to the motor, thereby dicing. The tension of the tape S is adjusted (step S16: tension adjusting process). Here, the relationship between the load and the drive amount of the drive unit 16 may be determined experimentally, or feedback control of the drive unit 16 may be performed according to the detected load.

  When the division of the wafer W is completed for all the division lines L (Yes in step S18), the process is completed.

  According to the present embodiment, the tension of the dicing tape S is reduced during the scanning of the wafer dividing jig 32 by monitoring the driving unit 16 and controlling the force applied to the frame F by the motor of the driving unit 16. Can be prevented.

  In the second embodiment, the drive unit 16 for driving the frame F is provided, but the present invention is not limited to this. Instead of or in addition to the drive unit 16 for driving the frame F, a drive unit for driving the push-up ring 30 may be provided. In this case as well, the applied pressure may be controlled by monitoring the load applied to the motor of the drive unit for driving the push-up ring 30 as in this embodiment.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a block diagram showing a wafer dividing apparatus according to the third embodiment of the present invention. In the following description, the same components as those in the first or second embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 9, the wafer dividing apparatus 10B includes a drive unit 16 as in the second embodiment.

  In the wafer dividing apparatus 10 </ b> B according to this embodiment, the detection unit 14 measures a load (load torque) applied to the jig driving motor 34 for scanning the wafer dividing jig 32. As the tension of the dicing tape S decreases, the load torque applied to the jig driving motor 34 decreases. Further, when a stick slip of the dicing tape S occurs, the load torque applied to the jig driving motor 34 periodically varies. In the present embodiment, a decrease in the tension of the dicing tape S is detected using this load torque.

  The control part 12 controls the drive part 16 according to the measured value of the load torque of the motor. Thereby, the balance between the tension of the dicing tape S and the force applied to the frame F by the drive unit 16 can be adjusted.

  Next, a wafer dividing method according to the third embodiment of the present invention will be described. The wafer dividing method according to this embodiment is mainly described in the tape tension determination step because the tape tension determination step is different from that of the second embodiment.

  FIG. 10 is a flowchart showing a tape tension determining step in the wafer dividing method according to the third embodiment of the present invention.

  In the tension determination step, first, the detection unit 14 measures the load torque applied to the jig driving motor 34 (step S140). And the control part 12 acquires the measured value of the load torque by the detection part 14, is a case where a load torque is more than a threshold value (No of step S142), and the cyclic | annular fluctuation | variation of a load torque is not seen. In this case (No in step S144), it is determined that there is no decrease in the tension of the dicing tape S (step S146).

  On the other hand, when the load torque is less than the threshold value (Yes in Step S142) or when a periodic variation in the load torque is detected (Yes in Step S144), the control unit 12 decreases the tension of the dicing tape S. It is determined that there is (step S148).

  In step S144, for example, the control unit 12 compares the measured value of the load torque with the measured value for the predetermined number of times immediately before to determine whether or not there is a periodic variation.

  If it is determined that the tension of the dicing tape S has not decreased, the control unit 12 continues to monitor the fluctuation of the tension of the dicing tape S. On the other hand, when it is determined that the tension of the dicing tape S is reduced, the control unit 12 controls the driving unit 16 to adjust the tension of the dicing tape S. The relationship between the load torque applied to the jig drive motor 34 and the drive amount of the drive unit 16 may be determined experimentally, or feedback control of the drive unit 16 is performed according to the detected load torque. May be.

  According to the present embodiment, by monitoring the jig driving motor 34 and controlling the driving unit 16, it is possible to prevent a decrease in the tension of the dicing tape S during the scanning of the wafer dividing jig 32. .

  In this embodiment, a sensor (for example, a strain gauge) that detects a force applied in the scanning direction of the wafer dividing jig 32 is provided instead of or in addition to the above configuration. You may make it measure the load concerning the wafer division | segmentation jig | tool 32 or the jig drive motor 34 with a sensor.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is a block diagram showing a wafer dividing apparatus according to the fourth embodiment of the present invention. In the following description, the same components as those in the first or second embodiment are denoted by the same reference numerals and description thereof is omitted.

  The wafer dividing apparatus 10C according to the present embodiment includes a laser displacement meter 50 for detecting the position of the tape surface of the dicing tape S. The laser displacement meter 50 measures the time until the pulsed laser is returned to the object and measures the distance to the tape surface of the dicing tape S by a TOF (Time Of Flight) method for converting the distance into a distance. . The laser displacement meter 50 is movable in the XY axis direction, and the distance between the laser displacement meter 50 and the tape surface of the dicing tape S can be measured at each part of the dicing tape S. .

  The detection unit 14 outputs the value of the distance from the laser displacement meter 50 to the tape surface of the dicing tape S to the control unit 12.

  The control unit 12 determines whether or not the tension of the dicing tape S is lowered according to the displacement measurement value acquired from the detection unit 14 and controls the drive unit 16. Thereby, the balance between the tension of the dicing tape S and the force applied to the frame F by the drive unit 16 can be adjusted.

  The means for measuring the displacement of the tape surface of the dicing tape S is not limited to the laser displacement meter 50, but it is preferable to use a sensor (displacement meter) that can measure the displacement without contact.

  FIG. 12 is a graph showing an example of displacement of the dicing tape when tension adjustment of the dicing tape is not performed. FIG. 13 is a graph showing the change over time of the displacement of the dicing tape when the tension of the dicing tape is adjusted. 12 and 13 indicate the amount of displacement of the dicing tape S. The horizontal axis in FIG. 12 indicates the moving direction (scanning direction, X-axis direction) of the wafer dividing jig 32, and the horizontal axis in FIG. 13 indicates time.

  When the tension of the dicing tape S is not adjusted, the dicing tape S bends due to a decrease in the tension, as shown in FIG. For this reason, the displacement of the dicing tape S periodically varies along the scanning direction of the wafer dividing jig 32.

  When the tension of the dicing tape S is adjusted, as shown in FIG. 13, when bending occurs with a decrease in the tension of the dicing tape S, the drive unit 16 is controlled, and the tension of the dicing tape S is adjusted and bent. Disappears. Thereby, the fall of the tension | tensile_strength of the dicing tape S can be prevented.

  Next, a wafer dividing method according to the fourth embodiment of the present invention will be described. The wafer dividing method according to this embodiment is mainly described in the tape tension determination step because the tape tension determination step is different from that of the second embodiment.

  FIG. 14 is a flowchart showing a tape tension determining step in the wafer dividing method according to the fourth embodiment of the present invention.

  In the tension determination step, first, the detection unit 14 measures the displacement of the dicing tape S with the laser displacement meter 50 (step S150). And the control part 12 acquires the measured value of the displacement by the laser displacement meter 50 via the detection part 14, is a case where the measured value of a displacement is less than a threshold value (No of step S152), and is the dicing tape S. If no vibration (periodic fluctuation of the displacement measurement value) is detected (No in step S154), it is determined that there is no decrease in the tension of the dicing tape S (step S156).

  On the other hand, when the measured value of displacement is equal to or greater than the threshold value (Yes in step S152) or when vibration of the dicing tape S is detected (Yes in step S154), the control unit 12 decreases the tension of the dicing tape S. It is determined that there is (step S158).

  In step S154, for example, the control unit 12 generates the deflection due to the decrease in the tension of the dicing tape S and the presence / absence of vibration based on the change over time of the displacement measurement value at the same position in the XY axis direction of the dicing tape S. Detection is performed. Further, the control unit 12 scans the laser displacement meter 50 in the XY-axis direction of the dicing tape S, compares the measured values of displacement at each position on the XY plane, and determines the deflection caused by the decrease in the tension of the dicing tape S. Detection of occurrence and vibration.

  If it is determined that the tension of the dicing tape S has not decreased, the control unit 12 continues to monitor the fluctuation of the tension of the dicing tape S. On the other hand, when it is determined that the tension of the dicing tape S is reduced, the control unit 12 controls the driving unit 16 to adjust the tension of the dicing tape S. The relationship between this displacement and the drive amount of the drive unit 16 may be determined experimentally, or feedback control of the drive unit 16 may be performed according to the detected displacement.

  According to the present embodiment, by monitoring the displacement of the dicing tape S and controlling the drive unit 16, it is possible to prevent a decrease in the tension of the dicing tape S during the scanning of the wafer dividing jig 32.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS. In the following description, the same components as those in the first or second embodiment are denoted by the same reference numerals and description thereof is omitted.

  FIG. 15 is a block diagram showing a wafer dividing apparatus according to the fifth embodiment of the present invention. In FIG. 15, the illustration of the vacuum source 36 and the piping 38 is omitted for simplification of the drawing.

  The wafer dividing apparatus 10 </ b> D according to the present embodiment includes a transmittance measuring unit including a light projecting light source 60 and a light receiving sensor 62. The light projecting light source 60 and the light receiving sensor 62 are provided so as to face each other with the dicing tape S therebetween, and can be scanned along the XY axis direction. The light projecting light source 60 emits light (for example, infrared light or visible light) toward the light receiving sensor 62. The light receiving sensor 62 receives light emitted from the light projecting light source 60.

  The detection unit 14 calculates the light transmittance of the dicing tape S by comparing the light amount of light emitted from the light projecting light source 60 with the light amount of light received by the light receiving sensor 62, and outputs the light transmittance to the control unit 12.

  The light transmittance of the dicing tape S varies depending on a stick slip or a change in the thickness of the dicing tape S. The control unit 12 detects a stick-slip or a change in thickness according to the transmittance measurement value acquired from the detection unit 14, determines whether the tension of the dicing tape S is reduced, and controls the drive unit 16. Control. Thereby, the balance between the tension of the dicing tape S and the force applied to the frame F by the drive unit 16 can be adjusted.

  FIG. 16 is a graph showing an example of the transmittance of the dicing tape when the tension of the dicing tape is not adjusted. FIG. 17 is a graph showing the change with time of the transmittance of the dicing tape when the tension of the dicing tape is adjusted. 16 and 17 indicate the light transmittance of the dicing tape S. The horizontal axis in FIG. 16 indicates the moving direction (scanning direction, X-axis direction) of the wafer dividing jig 32, and the horizontal axis in FIG. 17 indicates time.

  When the tension of the dicing tape S is not adjusted, as shown in FIG. 16, the thickness of the dicing tape S is changed due to the fluctuation of the tension or the occurrence of bending. For this reason, the light transmittance of the dicing tape S periodically varies along the scanning direction of the wafer dividing jig 32.

  When the tension of the dicing tape S is adjusted, as shown in FIG. 17, when the fluctuation of the tension of the dicing tape S occurs, the drive unit 16 is controlled to adjust the tension of the dicing tape S to change the transmittance. Disappears. Thereby, the fall of the tension | tensile_strength of the dicing tape S can be prevented.

  Next, a wafer dividing method according to the fifth embodiment of the present invention will be described. The wafer dividing method according to this embodiment is mainly described in the tape tension determination step because the tape tension determination step is different from that of the second embodiment.

  FIG. 18 is a flowchart showing a tape tension determination step in the wafer dividing method according to the fifth embodiment of the present invention.

  In the tension determination step, first, the detection unit 14 measures the transmittance of the dicing tape S (step S160). And the control part 12 acquires the measured value of the transmittance | permeability via the detection part 14, and when the fluctuation | variation of the transmittance | permeability is not detected (No of step S162), there is no fall of the tension | tensile_strength of the dicing tape S. Determination is made (step S164).

  On the other hand, when the fluctuation | variation of the transmittance | permeability is detected (Yes of step S162), the control part 12 determines with the tension | tensile_strength of the dicing tape S having fallen (step S166).

  In step S162, for example, the control unit 12 scans the light projecting light source 60 and the light receiving sensor 62 in the XY axis direction of the dicing tape S, compares the measured values of transmittance at each position on the XY plane, and The occurrence of bending due to the decrease in tension and the presence or absence of vibration are detected.

  If it is determined that the tension of the dicing tape S has not decreased, the control unit 12 continues to monitor the fluctuation of the tension of the dicing tape S. On the other hand, when it is determined that the tension of the dicing tape S is reduced, the control unit 12 controls the driving unit 16 to adjust the tension of the dicing tape S. The relationship between the transmittance and the drive amount of the drive unit 16 may be determined experimentally, or feedback control of the drive unit 16 may be performed according to the detected transmittance.

  According to the present embodiment, the transmittance of the dicing tape S is monitored and the drive unit 16 is controlled, so that a decrease in the tension of the dicing tape S during the scanning of the wafer dividing jig 32 can be prevented. .

  In the first to fifth embodiments, the suction port 32B is provided at the tip of the wafer dividing jig 32 so that the dicing tape S is vacuum-adsorbed to the wafer dividing jig 32. It is also possible not to provide. In the first to fifth embodiments, the wafer dividing jig 32 may be a convex member that contacts the back side of the wafer W or a concave member that contacts the back side of the wafer W. May be.

  In the first, second, fourth, and fifth embodiments, the wafer W is divided by applying only the tensile stress to the dicing tape S without providing the wafer dividing jig 32. Good. In the first, second, fourth and fifth embodiments, since the wafer dividing jig 32 is not essential, the table on which the workpiece is placed and the frame F are relatively moved. It is also possible to apply an expanding part.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described with reference to FIGS. FIG. 19 is a block diagram showing a wafer dividing apparatus according to the sixth embodiment of the present invention. In the following description, the same components as those in the first or second embodiment are denoted by the same reference numerals and description thereof is omitted.

  The wafer dividing apparatus 10E according to the present embodiment includes a pressure sensor 70 for measuring the pressure inside the pipe 38. As the pressure sensor 70, for example, a sensor that measures the deformation of the diaphragm provided in the pressure sensor 70 using a change in capacitance or a strain gauge can be used.

  When the tension of the dicing tape S decreases, the rigidity of the dicing tape S decreases. When the rigidity of the dicing tape S is lowered, the dicing tape S is loosened on the front side in the scanning direction of the wafer dividing jig 32 due to friction accompanying the scanning of the wafer dividing jig 32. For this reason, a gap is formed between the wafer dividing jig 32 and the dicing tape S, the suction pressure when the dicing tape S is sucked to the suction port 32B is lowered, and the pressure in the pipe 38 varies. When this slack is large, stick slip occurs, and when the dicing tape S slips with respect to the wafer dividing jig 32, the suction pressure is greatly reduced. In the present embodiment, the decrease in the tension of the dicing tape S is determined using this pressure fluctuation.

  The detection unit 14 according to the present embodiment acquires a measured value of the pressure in the pipe 38 by the pressure sensor 70 every predetermined time (for example, several seconds to several tens of seconds).

  The control unit 12 detects a stick-slip or a change in thickness according to the transmittance measurement value acquired from the detection unit 14, determines whether the tension of the dicing tape S is reduced, and controls the drive unit 16. Control. Thereby, the balance between the tension of the dicing tape S and the force applied to the frame F by the drive unit 16 can be adjusted.

  Next, a wafer dividing method according to the sixth embodiment of the present invention will be described. The wafer dividing method according to this embodiment is mainly described in the tape tension determination step because the tape tension determination step is different from that of the second embodiment.

  FIG. 20 is a flowchart showing a tape tension determination step in the wafer dividing method according to the sixth embodiment of the present invention.

  In the tension determination step, first, the detection unit 14 measures the pressure in the pipe 38 (step S170). And the control part 12 acquires the measured value of a pressure via the detection part 14, and when the fluctuation | variation of a pressure is not detected (No of step S172), it determines with the tension | tensile_strength reduction of the dicing tape S not having been detected. (Step S174).

  On the other hand, when the fluctuation | variation of a pressure is detected (Yes of step S172), the control part 12 determines with the tension | tensile_strength of the dicing tape S having fallen (step S176).

  In step S172, for example, the control unit 12 detects the occurrence of bending and the presence / absence of vibration due to a decrease in the tension of the dicing tape S based on, for example, a change in pressure measurement value over time.

  If it is determined that the tension of the dicing tape S has not decreased, the control unit 12 continues to monitor the fluctuation of the tension of the dicing tape S. On the other hand, when it is determined that the tension of the dicing tape S is reduced, the control unit 12 controls the driving unit 16 to adjust the tension of the dicing tape S. The relationship between this pressure and the drive amount of the drive unit 16 may be determined experimentally, or feedback control of the drive unit 16 may be performed according to the detected pressure.

  According to the present embodiment, the tension of the dicing tape S can be prevented from being lowered during the scanning of the wafer dividing jig 32 by monitoring the pressure of the pipe 38 and controlling the driving unit 16.

  In the second to sixth embodiments, as in the modification of the first embodiment, a dicing frame with low rigidity can be used to perform tension control for each direction using the deformation of the dicing frame. Is possible.

  In addition, the mechanisms for detecting a decrease in the tension of the dicing tape in the first to sixth embodiments can be used in combination.

  In addition, the application range of the wafer dividing apparatus and method according to the first to sixth embodiments is not limited to a silicon wafer, but may be applied to, for example, a wafer provided with a glass substrate, a piezoelectric wafer, or the like. Is possible.

  DESCRIPTION OF SYMBOLS 10, 10A, 10B, 10C, 10D, 10E ... Wafer dividing device, 12 ... Control part, 14 ... Detection part, 15 ... Tension adjusting mechanism, 16 ... Drive part, 18 ... Holding part, 30 ... Push-up ring, 32 ... Wafer dividing jig, 32A ... contact surface, 32B ... suction port, 34 ... jig driving motor, 36 ... vacuum source, 38 ... piping, 50 ... laser displacement meter, 60 ... light projecting light source, 62 ... light receiving sensor, 70 ... Pressure sensor, W ... Wafer, F ... Frame, S ... Dicing tape, C ... Chip

Claims (12)

An expanding portion for expanding a dicing tape to which a wafer on which a dividing line is formed and a frame surrounding the wafer is attached;
A tension adjusting unit that adjusts a tension applied to the dicing tape in accordance with a decrease in the tension of the dicing tape;
Wafer dividing apparatus comprising: The expanded part is
Expand ring,
A holding part for holding the frame,
The wafer dividing apparatus according to claim 1, wherein the dicing tape is expanded by relatively moving the expanding ring and the frame.   The wafer dividing apparatus according to claim 2, wherein the tension adjusting unit includes an air cylinder or a hydraulic cylinder for applying a constant force to the expanding ring or the frame. A detection unit for detecting a change in tension of the dicing tape;
A drive unit for relatively moving the expanding ring and the frame;
The said tension adjustment part adjusts the tension | tensile_strength added to the said dicing tape by controlling the said drive part, when it determines with the tension | tensile_strength of the said dicing tape falling based on the detection result by the said detection part. Wafer splitting equipment. The drive unit includes a motor for moving the expanding ring and the frame relatively,
The detection unit measures a load applied to the motor,
5. The wafer dividing apparatus according to claim 4, wherein the tension adjusting unit determines whether or not the tension of the dicing tape has decreased based on a load applied to the motor measured by the detection unit. The detection unit includes a displacement meter for measuring the displacement of the dicing tape,
6. The wafer dividing apparatus according to claim 4, wherein the tension adjusting unit determines whether the tension of the dicing tape has decreased based on the displacement of the dicing tape measured by the displacement meter. The detection unit includes a transmittance measuring unit for measuring the light transmittance of the dicing tape,
The said tension adjustment part determines whether the tension | tensile_strength of the said dicing tape fell based on the displacement of the said dicing tape measured by the said transmittance | permeability measurement part. Wafer splitting equipment.   8. The wafer dividing jig according to claim 4, further comprising a wafer dividing jig that abuts on a surface of the wafer on which the dicing tape is attached and applies a bending stress to a position where the division line is formed on the wafer. The wafer dividing apparatus according to claim 1. A jig driving motor for scanning the wafer dividing jig;
The detection unit measures a load applied to the jig driving motor,
The wafer dividing apparatus according to claim 8, wherein the tension adjusting unit determines whether the tension of the dicing tape has decreased based on a load applied to the jig driving motor measured by the detecting unit.   10. The wafer dividing apparatus according to claim 8, further comprising a vacuum source that performs vacuum suction through a suction port on a surface of the wafer dividing jig that contacts the surface of the wafer on which the dicing tape is attached. The detection unit includes a pressure sensor that measures a pressure in a pipe from the suction port to the vacuum source,
The wafer splitting apparatus according to claim 10, wherein the tension adjusting unit determines whether or not the tension of the dicing tape has decreased based on the pressure in the pipe measured by the pressure sensor. An expanding step of expanding a dicing tape to which a wafer on which a dividing line is formed and a frame surrounding the wafer is attached,
A tension adjusting step of adjusting a tension applied to the dicing tape in accordance with a decrease in the tension of the dicing tape;
A wafer dividing method comprising:

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