JP5913723B1 - Sheet peeling method and peeling apparatus - Google Patents

Abstract

Provided are a peeling method and a peeling device for peeling a stuck sheet while suppressing the work from being damaged even when the work to which the sheet is stuck is thin. A sheet peeling method is a sheet peeling method for sequentially peeling sheets adhered to a plurality of workpieces, wherein a base material surface of an m-th sheet peeled from an m-th workpiece is placed on a first surface. a sheet facing step for facing the base surface of the (m + 1) th sheet attached to the (m + 1) work, a sheet overlaying step for overlapping a part of the mth sheet on the (m + 1) th sheet, and the mth sheet And a heat-welding step of heat-welding the overlapping portion of the (m + 1) th sheet and a peeling step of peeling the (m + 1) -th sheet from the (m + 1) -th workpiece by pulling the m-th sheet. And a sheet | seat facing process, a sheet | seat superimposition process, a heat welding process, and a peeling process are repeated, and it is performed in order until peeling of the nth sheet | seat stuck on the nth workpiece | work. [Selection] Figure 2

Description

  The present invention relates to a sheet peeling method and a peeling apparatus.

  After the LSI pattern is exposed on the surface of the semiconductor wafer to form a plurality of devices, the back surface of the semiconductor wafer is ground to reduce the thickness of the semiconductor wafer before being divided into individual devices. At the time of grinding, a protective sheet is attached to the surface of the semiconductor wafer in order to prevent damage and contamination of the device formed on the semiconductor wafer. Then, the back surface of the semiconductor wafer is ground and the adhered protective sheet is peeled off before being divided into individual devices.

  In general, the protective sheet is peeled as follows. First, the peeling tape is attached to the protective sheet, and the protective sheet is peeled off from the surface of the semiconductor wafer by pulling up the peeling tape. (For example, patent document 1).

  There has also been proposed a method and apparatus for peeling a protective sheet from the surface of a semiconductor wafer without using a peeling tape (for example, Patent Document 2).

JP 2001-44144 A JP 2011-228626 A

  In Patent Document 2, the protective sheets are welded to each other by ultrasonic welding. However, when the semiconductor wafer to which the protective sheet is attached is thin, the semiconductor wafer is damaged by the load of the ultrasonic welding apparatus when performing ultrasonic welding. There is a fear.

  The present invention has been made in view of the above-mentioned matters, and the object of the present invention is to peel off the attached sheet while suppressing the work from being damaged even when the work to which the sheet is attached is thin. The present invention provides a peeling method and a peeling apparatus.

The sheet peeling method according to the first aspect of the present invention comprises:
It is a sheet peeling method for sequentially peeling sheets stuck to a plurality of workpieces,
A sheet facing step of facing the base material surface of the mth sheet peeled from the mth work to the base material surface of the m + 1th sheet attached to the m + 1th work;
A sheet superimposing step of superimposing a part of the m-th sheet on the m + 1-th sheet;
A heat welding step of heat-welding the overlapping portion of the m-th sheet and the m + 1-th sheet;
A peeling step of peeling the m + 1st sheet from the m + 1th workpiece by pulling the mth sheet,
Repeating the sheet facing step, the sheet superimposing step, the thermal welding step, and the peeling step, and sequentially performing the n-th sheet peeled to the n-th workpiece,
It is characterized by that.
(The above m and n are both natural numbers and satisfy the relationship of m <n.)

The sheet peeling apparatus according to the second aspect of the present invention provides:
A sheet peeling apparatus for sequentially peeling sheets attached to a plurality of workpieces,
A table on which a work with a sheet attached is placed;
A winding roller for winding and unwinding the sheet peeled from the workpiece;
A sheet orientation adjusting mechanism for facing the base material surface of the sheet unwound from the take-up roller to the base material surface of the sheet attached to the work placed on the table;
A sheet superposition mechanism that superimposes at least a part of the sheet unwound from the take-up roller on a work sheet placed on the table;
A heat welding device for heat welding a portion where the sheet unwound from the take-up roller and the sheet attached to the workpiece overlap,
A peeling mechanism that peels off the sheet attached to the workpiece by winding up the sheet that has been unwound by the winding roller, and
It is characterized by that.

Further, the thermal welding apparatus performs thermal welding alternately at the first welding position and the second welding position,
The sheet orientation adjusting mechanism may be configured such that the substrate surface of the unwound sheet is alternately directed at the first heat welding position and the second heat welding position.

Moreover, two said heat welding apparatuses are provided,
One of the thermal welding devices may perform thermal welding at the first thermal welding position, and the other thermal welding device may perform thermal welding at the second thermal welding position.

  In the sheet peeling method and peeling apparatus according to the present invention, since the base material surfaces of the sheets are opposed to each other, the sheets can be welded together by thermal welding. Thereby, even if the workpiece | work to which the sheet | seat was stuck is thin, a sheet | seat can be peeled, suppressing the damage of a workpiece | work. Moreover, since the base material side of the unwound sheet is brought into contact with the work, it is possible to prevent the work end from being pulled when the sheet adheres to and peels from the work end.

It is a perspective view of the semiconductor wafer to which the protective sheet was stuck. It is a side view which shows schematic structure of a peeling apparatus. It is a top view which shows schematic structure of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus. It is a side view explaining operation | movement of a peeling apparatus.

  The sheet peeling method according to the present embodiment is a sheet peeling method for sequentially peeling sheets adhered to a plurality of workpieces, and the base material surface of the mth sheet peeled from the mth workpiece, A sheet facing step for facing the base material surface of the (m + 1) th sheet attached to the (m + 1) th workpiece, a sheet overlaying step for stacking a part of the mth sheet on the (m + 1) th sheet, A thermal welding step of thermally welding the overlapping portion of the sheet and the (m + 1) th sheet, and a peeling step of peeling the (m + 1) th sheet from the (m + 1) th workpiece by pulling the mth sheet. And it peels sequentially to the nth sheet | seat stuck on the nth workpiece | work by repeating a sheet | seat facing process, a sheet | seat superimposition process, a heat welding process, and a peeling process. Note that m and n are both natural numbers and satisfy the relationship m <n.

  This sheet peeling method is realized by, for example, a sheet peeling apparatus described later. Hereinafter, the sheet peeling method and peeling apparatus according to the present embodiment will be described with reference to the drawings. Here, a description will be given with an example in which a semiconductor wafer is peeled off as a workpiece and a protective sheet attached to the semiconductor wafer is peeled off as a sheet.

  When producing a semiconductor device, a protective sheet is attached to the surface of the semiconductor wafer in order to reduce the thickness by grinding the back surface of the semiconductor wafer. As shown in FIG. 1, the protective sheet S includes a base surface BS that performs a protective function and a paste surface PS that performs an adhesive function. The paste surface PS contacts the surface of the semiconductor wafer W, and the base surface BS Is exposed. Then, after grinding, the protective sheet S is peeled off from the semiconductor wafer W as described below. The semiconductor wafer W to be used has the same shape, and the protective sheet S also has the same material and the same shape.

  As shown in FIGS. 2 and 3, the peeling device 1 includes a table 10, a take-up roller 20, a driving roller 21, a guide roller 22, thermal welding devices 30 and 31, sheet orientation adjusting devices 40 and 41, and a laser transmission receiver. 50, a reflection plate 51, a static eliminating device 60, and a control device 70.

  The table 10 is a mounting table on which the semiconductor wafer W to which the sheet S is attached is mounted. The table 10 is configured to reciprocate in the X-axis direction by a drive source such as a motor (not shown). The table 10 includes a positioning mechanism such as a positioning pin so that the semiconductor wafer W is placed at a fixed position. Further, the table 10 includes a holding mechanism for holding the semiconductor wafer W such as a suction mechanism so that the semiconductor wafer W is not lifted or displaced from the table 10 when the protective sheet S is peeled off.

  The take-up roller 20 is a roller that takes up the protective sheet S peeled from the semiconductor wafer W. The winding roller 20 is rotated by a driving source such as a motor (not shown). The take-up roller 20 is configured to be capable of normal rotation and reverse rotation as indicated by arrows. As will be described later, the end portion of the peeled protective sheet S and the end portion of the protective sheet S to be peeled are thermally welded, so that the protective sheet S is continuously wound around the winding roller 20.

  The drive roller 21 and the guide roller 22 are in contact with each other and arranged in parallel. The drive roller 21 is rotationally driven by a drive source such as a motor. As indicated by the arrows, the drive roller 21 is configured to be capable of forward drive and reverse drive. The guide roller 22 is configured to come into contact with the drive roller 21, and the protective sheet S is sandwiched between the guide roller 22 and the drive roller 21. When the driving roller 21 rotates, the guide roller 22 also rotates in conjunction with it, and the protective sheet S can be wound or unwound.

  The thermal welding devices 30 and 31 include a thermal welding part that can be moved up and down in the Z-axis direction, and heat and heat the peeled end of the protective sheet S and the peeled end of the protective sheet S as described later. The substrate surfaces BS are bonded to each other at the molecular level.

  As will be described later, the sheet orientation adjusting devices 40 and 41 adjust so that when the peeled protective sheet S is unwound, the unwound protective sheet S is sent in the X axis + direction or the X axis-direction. It is a device to do. Here, the sheet orientation adjusting devices 40 and 41 are air blowers, and the sheet orientation adjustment is performed so that the unwound protective sheet S is sent in the X-axis direction by the air blowing from the sheet orientation adjusting device 40. The unwound protective sheet S is sent in the X axis + direction by the air blow from the device 41.

  The laser transmission receiver 50 and the reflection plate 51 detect whether or not the protective sheet S has been completely peeled off from the semiconductor wafer W. As shown in FIG. 2, the laser transmitter / receiver 50 and the reflector 51 are provided below the driving roller 21 and the guide roller 22 and above the table 10, and as shown in the plan view of FIG. And the guide roller 22 are arranged so as to face each other in a skewed manner. As shown in FIG. 3, the laser emitted from the laser transmission receiver 50 is reflected by the reflection plate 51, and the laser transmission receiver 50 receives the reflected laser. As described above, the laser transmission receiver 50 and the reflection plate 51 are arranged such that the protective sheet S is separated from the semiconductor wafer W depending on whether or not the protective sheet S blocks the laser between the table 10 and the driving roller 21 and the guide roller 22. It is detected whether or not everything is peeled off.

  The static electricity removing device 60 removes static electricity generated when the protective sheet S is peeled off. The static eliminator 60 generates, for example, ions having positive and negative polarities, thereby ionizing air in the atmosphere and neutralizing static electricity with the generated ions. Thereby, static electricity generated when the protective sheet S is peeled is removed, and sticking of the protective sheet to the driving roller 21 and the guide roller 22 due to static electricity and adhesion of dust and the like to the semiconductor wafer W are suppressed.

  The control device 70 controls the operation of the peeling device 1, and controls the operations of the winding roller 20, the driving roller 21, the table 10, the thermal welding devices 30 and 31, and the sheet orientation adjusting devices 40 and 41. Control. Further, the control device 70 controls the laser transmission / reception in the laser transmission / reception receiver 50 and performs the above-described control based on the laser reception status of the laser transmission / reception receiver 50.

  Next, the sheet peeling operation of the peeling apparatus 1 will be described with reference to FIGS.

  First, the semiconductor wafer Wb is placed on the table 10. A protective sheet Sb is adhered to the semiconductor wafer Wb. Since the protective sheet Sb is bonded to the semiconductor wafer Wb by the glue surface PSb, the base material surface BSb is exposed.

  As shown in FIG. 4, the table 10 on which the semiconductor wafer Wb is placed moves until the leading end portion of the protective sheet Sb reaches the heat welding position of the heat welding device 30.

  Subsequently, as shown in FIG. 5, the unwinding roller 20 and the driving roller 21 rotate, and the protective sheet Sa that has been peeled and wound is unwound. Further, the unwinding protection sheet Sa is sent in the direction of the table 10 (X axis + direction) by the air blowing by the sheet orientation adjusting device 41. Then, after the protective sheet Sa is unwound from the unwinding roller 20 until the leading end portion of the protective sheet Sa reaches the heat welding position of the heat welding device 30, the driving of the unwinding roller 20 and the driving roller 21 is stopped.

  And the heat welding apparatus 30 descend | falls and welding of protective sheet Sa and protective sheet Sb is performed. The base material surfaces BSa and BSb of the protective sheets Sa and Sb are welded, and the protective sheet Sb is connected to the protective sheet Sa.

  Subsequently, as shown in FIG. 7, the take-up roller 20 and the drive roller 21 are driven to take up the protective sheet Sa. Further, the table 10 moves in the X-axis direction in synchronization with the driving of the winding roller 20 and the driving roller 21. Thereby, the protective sheet Sb is peeled from the semiconductor wafer Wb.

  Then, the table 10, the take-up roller 20 and the drive roller 21 are operated by the laser transmitter / receiver 50 and the reflection plate 51 until the protective sheet Sb does not block the laser. As shown in FIG. All the protective sheets Sb are peeled off.

  The table 10 returns to the original position, the semiconductor wafer Wb from which the protective sheet Sb has been peeled is removed, and the semiconductor wafer Wc to which the protective sheet Sc is attached is placed on the table 10 again.

  As shown in FIG. 9, the table 10 on which the semiconductor wafer Wc is placed moves until the tip portion of the protective sheet Sb reaches the heat welding position of the heat welding device 30.

  Subsequently, as shown in FIG. 10, the take-up roller 20 and the drive roller 21 rotate, and the protective sheet Sb that has been peeled off is unwound. Further, the protective sheet Sb unwound by blowing by the sheet orientation adjusting device 40 is sent in the direction of the table 10 (X axis + direction). The protective sheet Sb is unwound from the take-up roller 20 until the leading end portion of the protective sheet Sb reaches the heat welding position of the heat welding device 31, and the drive of the take-up roller 20 and the drive roller 21 is stopped.

  And the heat welding apparatus 31 descend | falls and welding of the protection sheet Sb and the protection sheet Sc is performed. The base material surfaces BSb and BSc of the protective sheets Sb and Sc are welded, and the protective sheet Sc is connected to the protective sheet Sb.

  Subsequently, as shown in FIG. 12, the take-up roller 20 and the drive roller 21 are driven to take up the protective sheet Sb. Further, the table 10 moves in the X axis + direction in synchronization with the driving of the winding roller 20 and the driving roller 21. Thereby, the protective sheet Sc is peeled from the semiconductor wafer Wc.

  Then, the table 10, the take-up roller 20 and the drive roller 21 are operated by the laser transmitter / receiver 50 and the reflecting plate 51 until the protective sheet Sc does not block the laser. As shown in FIG. All the protective sheets Sc will be peeled off.

  Thereafter, the above operation is repeated, and the protective sheet S is sequentially peeled from the plurality of semiconductor wafers W and wound around the winding roller 20.

  Thus, in the sheet peeling apparatus 1 according to the present embodiment, the base material surfaces BP of the protective sheet S face each other and are thermally welded. Since the adhesive surface PS does not intervene between the base material surfaces BP, it is possible to realize strong welding between the base material surfaces BP of the protective sheet S and to firmly bond the protective sheets S together. Accordingly, the protective sheet S can be pulled and peeled from the semiconductor wafer W without using a peeling tape.

  In ultrasonic welding, a load due to pressure and vibration is applied to the semiconductor wafer W, and if the semiconductor wafer W is thin, the semiconductor wafer W may be damaged. However, in the present embodiment, the protective sheets S are welded together by thermal welding, and the thermal welding does not apply pressure or vibration load to the semiconductor wafer W unlike ultrasonic welding. For this reason, in the present embodiment, the protective sheet S can be peeled from the thin semiconductor wafer W while suppressing damage to the semiconductor wafer W.

  In the above description, the sheet orientation adjusting devices 40 and 41 have alternately described the direction of the protective sheet S that is unwound by blowing. However, the base material surface BS of the peeled protective sheet S is about to be peeled. Any form may be used as long as it can be adjusted to face the base material surface BS of the protective sheet S. For example, the sheet orientation adjusting devices 40 and 41 may be suction devices capable of sucking the protective sheet S. In this case, in FIG. 5, the sheet orientation adjusting device 40 sucks the protective sheet Sa, and the protective sheet Sa is sent in the X axis + direction. In FIG. 10, the sheet orientation adjusting device 41 sucks the protective sheet Sa. Then, the protective sheet Sa is sent in the X-axis direction. Further, a gripping mechanism that grips the leading end portion of the protective sheet S protruding from the driving roller 21 and the guide roller 22 and moves the leading end portion of the protective sheet S to the thermal welding position of the thermal welding devices 30 and 31 may be used. .

  Moreover, although the form which the table 10 moves was demonstrated, whereas the table 10 should just be able to move relatively with respect to the drive roller 21, the guide roller, the heat welding apparatus 30, 31, etc., whereas the table 10 is fixed. The drive roller 21, the guide roller 22, the heat welding devices 30, 31 and the like may move.

  Moreover, the detection apparatus which detects whether the front-end | tip part of the unwound protective sheet S reached | attained the heat welding position may be installed. For example, a detection device similar to the laser transmitter / receiver 50 and the reflector 51 described above can be used.

  Moreover, although the form provided with the two heat welding apparatuses 30 and 31 was demonstrated, the form which one heat welding apparatus moves to a welding position one by one and welds may be sufficient.

DESCRIPTION OF SYMBOLS 1 Separation apparatus 10 Table 20 Winding roller 21 Drive roller 22 Guide roller 30, 31 Thermal welding apparatus 40, 41 Sheet orientation adjustment apparatus 50 Laser transmission receiver 51 Reflector plate 60 Static electricity removal apparatus 70 Control apparatus W, Wb, Wc Semiconductor wafer S, Sa to Sc Protective sheet BS, BSa to BSc Base material surface PS, PSa to PSc Adhesive surface

Claims (4)

It is a sheet peeling method for sequentially peeling sheets stuck to a plurality of workpieces,
A sheet facing step of facing the base material surface of the mth sheet peeled from the mth work to the base material surface of the m + 1th sheet attached to the m + 1th work;
A sheet superimposing step of superimposing a part of the m-th sheet on the m + 1-th sheet;
A heat welding step of heat-welding the overlapping portion of the m-th sheet and the m + 1-th sheet;
A peeling step of peeling the m + 1st sheet from the m + 1th workpiece by pulling the mth sheet,
Repeating the sheet facing step, the sheet superimposing step, the thermal welding step, and the peeling step, and sequentially performing the n-th sheet peeled to the n-th workpiece,
A sheet peeling method characterized by the above.
(The above m and n are both natural numbers and satisfy the relationship of m <n.) A sheet peeling apparatus for sequentially peeling sheets attached to a plurality of workpieces,
A table on which a work with a sheet attached is placed;
A winding roller for winding and unwinding the sheet peeled from the workpiece;
A sheet orientation adjusting mechanism for facing the base material surface of the sheet unwound from the take-up roller to the base material surface of the sheet attached to the work placed on the table;
A sheet superposition mechanism that superimposes at least a part of the sheet unwound from the take-up roller on a work sheet placed on the table;
A heat welding device for heat welding a portion where the sheet unwound from the take-up roller and the sheet attached to the workpiece overlap,
A peeling mechanism that peels off the sheet attached to the workpiece by winding up the sheet that has been unwound by the winding roller, and
A sheet peeling apparatus. The thermal welding apparatus performs thermal welding alternately at the first welding position and the second welding position,
The sheet orientation adjusting mechanism is configured so that the substrate surface of the unwound sheet is alternately directed at the first heat welding position and the second heat welding position.
The sheet peeling apparatus according to claim 2. Two heat welding devices are provided,
One of the thermal welding devices performs thermal welding at the first thermal welding position, and the other of the thermal welding devices performs thermal welding at the second thermal welding position.
The sheet peeling apparatus according to claim 3.

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