JP2008153338A - Dividing method of wafer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To divide a wafer into individual semiconductor devices in most economical manner while the wafer is divided into a plurality of pieces on an adhesive film during pasting or after it is pasted. <P>SOLUTION: The shape and position of pieces 1a-1c of a wafer 1 having been divided into a plurality of pieces 1a-1c on an adhesive film 5 are recognized in an recognizing process that uses a transmitted illumination. Based on the recognizing result, such alignment as recognizes a scheduled cutting line for each of the pieces 1a-1c is performed in an alignment process. Based on the recognizing result and alignment result, a dividing process is performed along the scheduled cutting line for each of the divided pieces 1a-1c of the wafer 1 on the adhesive film 5 in a dividing process. So, while the wafer 1 is divided into a plurality of pieces 1a-1c on the adhesive film 5 during pasting or after pasting, the pieces 1a-1c of indeterminate form are separated properly into individual semiconductor devices. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for dividing a wafer bonded to an opening by an adhesive film on a frame having the opening.

  Wafers on which a plurality of semiconductor devices such as IC and LSI are formed are ground to have a predetermined thickness by grinding the back surface, and are divided into individual devices by a processing device such as a dicing device, and electronic devices such as mobile phones and personal computers Used for Here, a die bonding sheet that functions as a protective tape at the time of dicing, and also functions as an adhesive for die bonding when die-bonding a chip of a semiconductor device to a lead frame after dicing is applied to the back surface of the wafer. A die bonding sheet sticking apparatus and a die bonding sheet sticking method for sticking to a sheet have been proposed (for example, see Patent Document 1).

JP 2002-367931 A Japanese Patent No. 3173552 Japanese Patent No. 2991593

  By the way, when a wafer having a thickness of about 50 μm is attached to the wafer and held on the frame by thinning the wafer in recent years, the wafer is cracked due to warpage of the wafer or the like. It causes a problem such as damage.

  At this time, if the wafer is attached with a normal adhesive film having low adhesive strength, it is easy to remove the broken wafer fragments from the adhesive film. By reattaching on the film, dicing of each irregular shaped piece can be made possible (see, for example, Patent Document 2).

  On the other hand, it is very difficult to peel the damaged wafer from the die bonding sheet. For this reason, as a countermeasure when the wafer on the die bonding sheet is damaged such as a crack, the broken wafer is not peeled off and reattached. In addition, it is conceivable to perform alignment (alignment) of the lines to be cut and dice only the fragments. However, such countermeasures are uneconomical because other pieces cannot be processed along the proper cutting line because they cannot be processed.

  The present invention has been made in view of the above, and at the time of sticking or after sticking, the wafer is divided into a plurality of pieces on the adhesive film, and the wafer is made into individual semiconductor devices as economically as possible. It is an object of the present invention to provide a method for dividing a wafer that can be divided into pieces.

  In order to solve the above-described problems and achieve the object, the wafer dividing method according to the present invention is a method in which a wafer having a plurality of semiconductor devices surrounded by a line to be cut is formed on the surface larger than the outer diameter of the wafer. A wafer that is attached to the opening by an adhesive film on a frame having an opening, and the wafer divided into a plurality of pieces on the adhesive film at the time of or after the attachment is divided along a scheduled cutting line on the surface. A recognition method for recognizing the shape and position of each piece of the wafer that has been divided, and an alignment step for recognizing a cutting line on the surface of each piece of the wafer whose shape and position have been recognized in the recognition step Information on the shape and position of each piece of wafer recognized in the recognition step and the expected cutting line of each piece of wafer recognized in the alignment step. And having a dividing step of dividing each strip of the wafer along the line to cut each piece based on the location of the information.

  Further, the wafer dividing method according to the present invention is the above invention, wherein the dividing step uses a cutting means having a spindle on which a cutting blade is rotatably mounted, and each piece of the wafer held on the chuck table is scheduled to be cut. It is executed by cutting along the line with the cutting blade, and the cutting blade is processed from a position corresponding to the outer edge before the wafer is divided into a plurality of pieces to a position corresponding to the inner peripheral side. It is characterized in that the workpiece is relatively processed and fed by a feeding means and retracted in a direction away from the holding surface of the chuck table when the piece reaches the divided position.

  Further, in the wafer dividing method according to the present invention, in the above invention, the recognition step transmits the wafer held through the adhesive film with respect to the frame from the surface side and the adhesive film. The illuminating means for irradiating the illumination light from the back side is used, and the divided position is extracted by performing image processing on an image signal obtained by receiving the transmitted light of the illumination light emitted by the illuminating means with the imaging means. And recognizing the shape and position of each piece of the wafer.

  According to the method for dividing a wafer according to the present invention, the shape and position of each piece of the wafer divided into a plurality of pieces on the adhesive film is recognized in the recognition step, and cutting is performed for each piece in the alignment step based on the recognition result. By performing alignment that recognizes the planned line, and performing the dividing process along the planned cutting line for each piece of the wafer on the adhesive film divided by the dividing process based on the recognition result and the alignment result, After sticking, the wafer is divided into a plurality of pieces on the adhesive film, and each piece having an irregular shape can be properly divided into individual semiconductor devices. There is an effect that the semiconductor device can be singulated as economically as possible so as to make use of most of the semiconductor devices on the wafer other than the semiconductor devices.

  Hereinafter, a wafer dividing method which is the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view showing a configuration example of a wafer cutting apparatus to which the wafer dividing method of the present invention is applied, and FIG. 2 is a perspective view showing a part for executing a recognition process.

  First, an example of a wafer to which the wafer dividing method according to the present embodiment is applied will be described with reference to FIG. A wafer 1 applied to this embodiment has a circular shape with a thickness of about 50 μm in which a plurality of semiconductor devices 3 surrounded by lines to be cut 2 set vertically and horizontally so as to have a lattice shape are formed on the surface. It is a thing attached to the opening 4a by the adhesive film 5 on the metal annular frame 4 having a circular opening 4a larger than the outer diameter of the wafer 1. Here, the adhesive film 5 functions as a protective tape at the time of dicing, and also functions as an adhesive for die bonding when the chip of the semiconductor device 3 is die-bonded to the lead frame after being diced. A strong die bonding sheet is used. When the adhesive film 5 is attached or after being attached, a crack is generated due to the warp of the wafer 1 or the like, and a plurality of pieces are formed on the adhesive film 5 in an irregular shape, an irregular size, an indefinite number of pieces, for example, FIG. A wafer 1 divided into three pieces 1a, 1b, and 1c as shown in FIG.

  As described above, the wafer cutting apparatus according to the present embodiment that cuts the wafer 1 that has been divided into a plurality of pieces 1a to 1c on the adhesive film 5 is roughly composed of an illumination unit 10 and an imaging unit. 20, a chuck table 30, a cutting means 40, an imaging means 50, a cleaning / drying means 60, and a control means 70 for controlling the operation of each part.

  The chuck table 30 has a holding surface 31 made of a porous material for adsorbing and holding the wafer 1 supported by the frame 4 via the adhesive film 5 by a suction force of a negative pressure source (not shown). It is connected and is rotatable in a horizontal plane (XY plane). The chuck table 30 is provided so as to be processed and fed in the X-axis direction by a processing feed means (not shown), and the rectangular table cover 32 surrounding the chuck table 30 follows the machining feed at both ends in the X-axis direction. Then, the bellows member 33 that extends and contracts and waterproofs the lower processing feed means is locked. In addition, a clamp 34 is provided at the peripheral portion of the chuck table 30 to detachably hold the frame 4 portion on which the directionality is specified by a conveying means (not shown).

  The cutting means 40 has a spindle 42 on which a cutting blade 41 for cutting the wafer 1 held on the chuck table 30 is rotatably mounted, and can be indexed and fed in the Y-axis direction by an index feed means (not shown). In addition, it is provided so that it can be cut and fed in the Z-axis direction orthogonal to the XY plane by a not-shown cutting feed means. The periphery of the cutting blade 41 is covered with a blade cover 43, and cutting water for cooling the cutting blade 41 or washing away the cutting waste at the time of cutting is sprayed toward the cutting point of the cutting blade 41. A pair of front and back spray nozzles 44 are provided.

  The image pickup means 50 is for mounting an image pickup device such as a CCD camera in which a large number of pixels are arranged in the XY plane and picks up an image of the surface of the wafer 1 held on the chuck table 30. 41 is provided integrally with a part of the spindle 42 so as to always move while maintaining a predetermined positional relationship. The control means 70 performs image processing such as pattern matching for aligning the scheduled cutting line 2 formed in the predetermined direction of the wafer 1 with the cutting blade 41 based on the image information acquired by the imaging means 50. And performing the alignment of the cutting position, thereby providing the positioning of the cutting operation by the cutting means 40.

  The cleaning / drying means 60 is configured such that the frame 4 having the cut wafer 1 on the adhesive film 5 on which the cutting process has been completed is transported onto the spinner table 61 and the wafer 1 supported on the frame 4 is rotated at a high speed. Are sprayed and washed, air is blown to dry, and then sent to the next step.

  The illumination means 10 is provided on the upstream side in the X-axis direction with respect to the chuck table 30 on which cutting is performed, and is used for the recognition process. The illumination means 10 is disposed in the XY plane and transmits the adhesive film 5. Also functions as a holding member on which a plurality of fluorescent lamps 11 that irradiate light from the lower surface side that is the back surface of the wafer 1 and the wafer 1 that is positioned above the fluorescent lamps 11 and is to be recognized are placed together with the frame 4. And a diffusing member 12 having light transmittance for irradiating the back surface of the wafer 1 substantially uniformly with the illumination light emitted from the fluorescent lamp 11 as diffused light. The wafer 1 is transported between the diffusing member 12, the chuck table 30, and the spinner table 61 by gripping a predetermined position of the frame 4 by the transport unit (not shown).

  The imaging means 20 is mounted on the frame 4 by mounting an imaging element such as a CCD camera in which a large number of pixels are arranged in the XY plane in order to recognize the shape and position of each of the divided pieces 1a to 1c of the wafer 1. On the other hand, the wafer 1 held via the adhesive film 5 is imaged from the upper surface side, which is the surface, and has almost the same structure as the imaging means 50 and is arranged to face the illumination means 10.

  The control means 70 controls the operation of each part such as the illumination means 10, the imaging means 20, 50, the cutting means 40, etc., and performs the recognition process, the alignment process, and the dividing process in order using the built-in storage unit, thereby causing the adhesion. Cutting is performed on the wafer 1 in a state of being divided into pieces 1 a to 1 c on the film 5.

  Hereinafter, the method for dividing the wafer 1 according to the present embodiment executed under the control of the control means 70 will be described in order. First, the frame 4 on which the wafer 1 to be cut is mounted via the adhesive film 5 is transported and placed on the diffusing member 12 by the transport means, and the recognition process is executed. In this recognition step, a plurality of fluorescent lamps 11 are turned on simultaneously to illuminate the wafer 1 placed on the diffusing member 12 from the back side. At this time, since the illumination light from the fluorescent lamp 11 is illuminated through the diffusing member 12, the back surface side of the wafer 1 is irradiated as uniform diffused light in a surface-emitting manner. In such an illumination state, the imaging means 20 is moved to an imaging position where the wafer 1 is directly below, and the entire wafer 1 supported by the frame 4 via the adhesive film 5 is collectively imaged from the surface side. The light transmitted through the illumination light irradiated by the illumination means 10 is received by the CCD camera, thereby obtaining an image signal accompanied by light and dark.

  At this time, the wafer 1 is stuck and supported on the adhesive film 5 stretched with respect to the frame 4, and when the plurality of pieces 1 a to 1 c are divided due to wafer warpage or the like, the dividing position is obtained. A crack 6 due to the spread of the pieces 1a to 1c occurs, and the adhesive film 5 is exposed along the crack 6. In the recognition process, since the wafer 1 in such a state is imaged by the imaging means 20 from the front side while illuminating from the back side, the illumination light is blocked and does not pass through the portions where the pieces 1a to 1c exist. In the periphery of the wafer 1 and the portion of the crack 6, the wafer material does not exist and only the adhesive film 5 exists, so that the illumination light is transmitted. Therefore, as shown schematically in FIG. 3, the image information of the wafer 1 obtained by imaging by the imaging means 20 is dark in the portions where the pieces 1a to 1c exist, but at the periphery of the wafer 1 and at the dividing position. A certain crack 6 portion becomes light and dark information that becomes whitish. Therefore, by performing a binarization process on the image signal received by the imaging unit 20 using a predetermined threshold value appropriately set, XY composed of a large number of pixels arranged in the XY plane of the CCD camera. The dividing position is extracted on the axis matrix, and the shape of each divided piece 1a to 1c and the position on the XY axis matrix where each piece 1a to 1c exists are recognized. In addition, based on the information on the shape and position, the alignment stroke for each piece 1a to 1c is calculated, and the control means 70 has the information on the shape and position of the recognized pieces 1a to 1c and the information on the alignment stroke. Store in the storage unit.

  After completion of the recognition process, the frame 4 on which the wafer 1 to be cut is mounted via the adhesive film 5 is transported and placed on the chuck table 30 from the diffusion member 12 by the transporting means, and the shape and position are set. , The alignment process of each piece 1a to 1c of the wafer 1 is recognized. First, an imaging position at which the wafer 1 is directly below the imaging means 50 by feed control in the X-axis direction of the chuck table 30 by the machining feed means and feed control in the Y-axis direction of the cutting means 40 (imaging means 50) by the index feed means. Based on the information obtained in the recognition process and stored in the storage unit, the cutting planned line 2 on the surface side of the wafer 1 supported by the adhesive film 5 with respect to the frame 4 is imaged. At the position where each piece 1a to 1c of the wafer 1 is present, a more precise alignment process is executed by a known pattern matching process.

  That is, for each of the pieces 1a to 1c in the wafer 1, for example, how much the planned cutting line 2 in both the vertical and horizontal directions for cutting the piece 1a is displaced with respect to the XY axis, and how much is inclined in angle. Is accurately detected by pattern matching according to the alignment stroke calculated and stored in advance, and the positional deviation on the XY axis and the inclination angle thereof are stored as alignment information in the storage unit of the control means 70. At this time, the cutting stroke of the cutting means 40 corresponding to the size and shape of the piece 1a includes, for example, a cutting stroke in the X-axis direction as shown in FIG. 4 and a cutting stroke in the Y-axis direction as shown in FIG. These stroke information is also stored in the storage unit of the control means 70 as alignment information. As shown in FIGS. 4 and 5, the cutting stroke in this case is from the outside of the wafer 1 to the position immediately after reaching the divided position where the piece 1a is divided. Similarly, regarding the planned cutting line 2 in both the vertical and horizontal directions for cutting the other pieces 1b and 1c, information on the positional deviation and the inclination angle and information on the cutting strokes in the X and Y axis directions are detected as alignment information. , And stored in a storage unit included in the control means 70.

  When the alignment process of each piece 1a to 1c of the wafer 1 is completed, the control means 70 is recognized in the recognition process and information on the shape and position of each piece 1a to 1c stored in the storage unit and recognized in the alignment process. The processing feed means, the index feed means, and the cutting based on the information on the positional deviation, the inclination angle, and the cutting strokes in the X and Y axis directions, which are the position information of the scheduled cutting lines 2 of the pieces 1a to 1c stored in the storage unit By controlling the operations of the feeding means of the feeding means and the motor for the chuck table and causing the cutting means 40 to perform the cutting operation, the pieces 1a to 1c of the wafer 1 on the chuck table 30 are changed to the pieces 1a to 1c. The dividing step of dividing along the scheduled cutting line 2 is performed.

  That is, for each of the pieces 1a to 1c in the wafer 1, for example, in order to cut the piece 1a, the piece 1b is positioned at the cutting position by the rotation of the chuck table 30, and one cutting planned line 2 of the piece 1a is in the X axis. The chuck table 30 is rotated by an inclination angle by the chuck table motor so as to coincide with the direction so as to align the direction of the piece 1a of the wafer 1, and the interrupt feed means so as to position the cutting blade 41 on the desired cutting line 2 The cutting means 40 is interrupted and fed, and while the cutting blade 41 is rotated at a high speed, the cutting means 40 is cut and fed by a predetermined amount by the cutting and feeding means and processed and fed in the X-axis direction by the machining and feeding means. A desired cutting scheduled line 2 is cut. When the machining feed for the cutting stroke stored for the scheduled cutting line 2 is performed, the cutting blade 41 is retracted in the direction away from the wafer 1 by the separation operation by the cutting feed means, and returned in the X-axis direction, The operation after the interruption sending for the next scheduled cutting line 2 of the piece 1a is repeatedly executed in the same manner.

  At this time, as indicated by an arrow in FIG. 6A, the cutting blade 41 is directed from a position corresponding to the outer edge before the wafer 1 is divided into a plurality of pieces 1a to 1c to a position corresponding to the inner peripheral side. Then, the cutting blade 41 is cut by retreating the cutting blade 41 in the direction away from the holding surface 31 of the chuck table 30 by the cutting feed means immediately after reaching the divided cutting position of the piece 1a. Advance the movement.

  When the cutting operation for one scheduled cutting line 2 of the piece 1a is completed, the chuck table 30 (piece 1a) is rotated 90 degrees by the chuck table motor, and the direction of the other scheduled cutting line 2 of the piece 1a of the wafer 1 is turned. Is aligned with the X-axis direction, the cutting means 40 is interrupted and fed by the interrupt feeding means so that the cutting blade 41 is positioned on the desired cutting line 2, and the cutting means 40 is cut and fed while the cutting blade 41 is rotated at a high speed. The desired cutting scheduled line 2 of the piece 1a is cut by feeding the workpiece in the X-axis direction by the machining feed means while cutting and feeding a predetermined amount by the means. When the machining feed for the cutting stroke stored for the scheduled cutting line 2 is performed, the cutting blade 41 is retracted in the direction away from the wafer 1 by the separation operation by the cutting feed means, and returned in the X-axis direction, The operation after the interruption sending for the next scheduled cutting line 2 of the piece 1a is repeatedly executed in the same manner.

  Also in this case, as shown in FIG. 6B, the cutting blade 41 is directed from the position corresponding to the outer edge before the wafer 1 is divided into the plurality of pieces 1a to 1c to the position corresponding to the inner peripheral side. The cutting operation is performed by the processing feed means, and the cutting blade 41 is retracted in the direction away from the holding surface 31 of the chuck table 30 by the cutting feed means immediately after reaching the divided position where the piece 1a is divided. To advance.

  When the cutting operation of the vertical and horizontal cutting scheduled lines 2 for the piece 1a portion in the wafer 1 is completed, this time, for example, in order to cut the piece 1b, the piece 1b is positioned at the cutting position by rotating the chuck table 30. The chuck table 30 is rotated by an inclination angle so that one cutting scheduled line 2 of the piece 1b coincides with the X-axis direction to align the direction of the piece 1b of the wafer 1 and a desired cutting scheduled line. The cutting means 40 is interrupted and fed by the interruption feeding means so that the cutting blade 41 is positioned at 2, and the cutting means 40 is cut and fed by a predetermined amount with the cutting feeding means while the cutting blade 41 is rotated at a high speed. By cutting and feeding in the axial direction, the desired cutting scheduled line 2 of the piece 1b is cut. When the machining feed for the cutting stroke stored for the scheduled cutting line 2 is performed, the cutting blade 41 is retracted in the direction away from the wafer 1 by the separation operation by the cutting feed means, and returned in the X-axis direction, The operations after the interrupt transmission for the next scheduled cutting line 2 of the piece 1b are repeated in the same manner. The cutting operation is performed in the same manner for the other scheduled cutting line 2 orthogonal to one scheduled cutting line 2 of the piece 1b.

  When the cutting operation of the vertical and horizontal cutting planned lines 2 for the pieces 1a and 1b in the wafer 1 is completed, the cutting operation for the cutting planned lines 2 is similarly performed on the remaining pieces 1c, whereby all the pieces 1a to 1c are processed. The division | segmentation process for every piece 1a-1c about is completed.

  The wafer 1 on the frame 4 that has undergone the division process is conveyed to the cleaning / drying means 60 by the conveying means, and after being subjected to the cleaning / drying process, is sent to the next process.

  Thus, according to the wafer dividing method according to the present embodiment, the shape and position of each piece 1a-1c of the wafer 1 divided into a plurality of pieces 1a-1c on the adhesive film 5 are recognized in the recognition step. Then, alignment is performed for recognizing the cutting scheduled lines 2 for each of the pieces 1a to 1c based on the recognition result, and the wafer 1 on the adhesive film 5 is divided by the dividing step based on the recognition result and the alignment result. By performing the dividing process along the scheduled cutting line 2 for each of the pieces 1a to 1c, the wafer 1 remains in a state of being divided into a plurality of pieces 1a to 1c on the adhesive film 5 at the time of sticking or after sticking. Each piece 1a to 1c having a fixed shape can be separated into individual semiconductor devices 3 appropriately. Therefore, the semiconductor device 3 can be separated into pieces as economically as possible so as to make use of most of the semiconductor devices 3 on the wafer 1 other than the semiconductor devices 3 around the dividing position.

  Further, according to the wafer dividing method according to the present embodiment, the dividing step is performed using each of the wafers 1 held on the chuck table 30 using the cutting means 40 having the spindle 42 on which the cutting blade 41 is rotatably mounted. The position corresponding to the outer edge before the wafer 1 is divided into a plurality of pieces 1a to 1c, which is executed by cutting the pieces 1a to 1c with the cutting blade 41 along the planned cutting line 2 From the holding surface 31 of the chuck table 30 at the time of reaching the divided position by the machining feed means toward the position corresponding to the inner peripheral side, and the cutting start operation is In the same manner as in the prior art, the cutting start speed is not reduced so much, and the cutting thread for other pieces adjacent to each other through the dividing position (break 6) is cut. Due to the less affected as much as possible short stroke can be reduced as much as possible the number of semiconductor devices 3 which would waste.

  Further, according to the wafer dividing method according to the present embodiment, the recognition step includes the imaging unit 20 and the adhesive film 5 for imaging the wafer 1 held on the frame 4 via the adhesive film 5 from the surface side. Using the illuminating means 10 that irradiates transmitted illumination light from the back side, the image signal obtained by the imaging means 20 receiving the transmitted light of the illumination light emitted by the illuminating means 10 is subjected to image processing to determine the dividing position. Since the shape and position of each piece 1a to 1c of the wafer 1 divided by extraction are recognized, the division position between the pieces 1a to 1c can be reliably extracted, and the wafer 1 is divided. Moreover, the recognition accuracy of the shape and position of each piece 1a-1c can be improved. In particular, since the illumination unit 10 emits illumination light as uniform diffused light, highly accurate shape and position recognition operations can be performed stably.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the present embodiment, after the shape and position of each of the pieces 1a to 1c divided in the wafer 1 are recognized in the recognition step, the alignment step and the division step are executed for all the pieces 1a to 1c. The size is recognized from the shape and position of each piece of the wafer 1 divided in the recognition step. For example, only pieces of a size larger than a predetermined size that can include a predetermined number of semiconductor devices are subjected to the alignment step and the division step. A step of selecting may be added. As a result, it is possible to perform the processing only on the piece for which the singulation is effective, and to eliminate the unnecessary alignment step and division step.

  In the present embodiment, the recognition process is performed at a place different from the alignment process. However, for example, a large number of light emitting elements such as LEDs are embedded in the holding surface 31 portion of the chuck table 30, and An illumination process is performed by irradiating illumination light from the back surface side of the wafer 1 held by the adhesive film 5 with a large number of light emitting elements and receiving light transmitted from the front surface side of the wafer 1 by the imaging means 50 for alignment. May be executed. Further, in the present embodiment, a plurality of fluorescent lamps 11 are used as the light source of the illumination means 10, but a planar light emitting element or the like may be used.

  Further, in the present embodiment, the cutting stroke for each piece 1a to 1c is set to be separated from the cutting blade 41 at a position immediately after the cutting position is reached, but each piece 1a to 1c, for example, in FIG. As shown, the cutting stroke may be set so that the cutting blade 41 is separated from the piece 1a at a position immediately before reaching the dividing position. According to this, the cutting operation on the piece does not affect the cutting operation on the other piece at all, and the number of semiconductor devices 3 that are wasted when the cutting stroke exceeds the cutting position can be reduced.

  Alternatively, as shown in FIG. 8, for each of the pieces 1 a to 1 c, for example, in the portion of the piece 1 a, the cutting stroke with respect to the vertical and horizontal cutting scheduled lines 2 is targeted only for the portion where the semiconductor device 3 that can be normally divided exists. By setting the rectangular staircase shape, it is possible to execute a lean dividing operation for separating only the semiconductor devices 3 that can be normally divided.

  Moreover, although this Embodiment demonstrated by the example using the cutting means 40 which cuts mechanically using the cutting blade 41 as a cutting means, the laser beam which irradiates a laser beam along the cutting scheduled line 2 of the wafer 1 You may make it use the cutting means by an irradiation means. Further, in the present embodiment, the example in which the dividing step is performed using one cutting means 40 has been described. However, for example, the wafer 1 is divided by providing two stages of cutting means in the X-axis direction that is the machining feed direction. In addition, the present invention can be similarly applied to a step cut in which cutting operations are performed in two stages of a half cut and a full cut on the same scheduled cutting line of each piece 1a to 1c.

  Moreover, in this Embodiment, although the die-bonding sheet | seat from which peeling of the wafer 1 is difficult was used as the adhesive film 5, even when the dicing tape which functions as a protective tape at the time of dicing is used, it applies similarly. be able to. In this case, it is possible to save the trouble of peeling off the pieces 1a to 1c from the dicing tape and attaching them again.

It is a schematic perspective view which shows the structural example of the wafer cutting device with which the division | segmentation method of the wafer of this invention is applied. It is a perspective view which extracts and shows the part which performs a recognition process. It is a perspective view which shows typically the example of a wafer image obtained by imaging with an imaging means in a recognition process. It is a perspective view which shows typically the example of one cutting stroke setting about one piece. It is a perspective view which shows typically the other cutting stroke setting example about one piece. It is a perspective view which shows typically the result example of the division | segmentation process about one piece in order of a process. It is a perspective view which shows typically the other example of cutting stroke setting. It is a perspective view which shows typically another example of cutting stroke setting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wafer 1a-1c Piece 2 Planned cutting line 3 Semiconductor device 4 Frame 5 Adhesive film 10 Illuminating means 20 Imaging means 30 Chuck table 31 Holding surface 40 Cutting means 41 Cutting blade 42 Spindle

Claims (3)

A wafer having a plurality of semiconductor devices surrounded by a line to be cut is formed on the surface, and is attached to the opening with an adhesive film on a frame having an opening larger than the outer diameter of the wafer. A wafer dividing method for dividing a wafer, which is later divided into a plurality of pieces on an adhesive film, along a cutting scheduled line on the surface,
A recognition process for recognizing the shape and position of each piece of the wafer divided;
An alignment step of recognizing a line to be cut on the surface of each piece of the wafer whose shape and position are recognized in the recognition step;
Each piece of the wafer is cut into each piece based on the information on the shape and position of each piece of the wafer recognized in the recognition step and the information on the position of the planned cutting line of each piece of the wafer recognized in the alignment step. A dividing step of dividing along a planned line;
A method of dividing a wafer, comprising:   The dividing step is performed by cutting each piece of the wafer held on the chuck table with the cutting blade along a planned cutting line using a cutting means having a spindle on which a cutting blade is rotatably mounted, and The cutting blade is relatively processed by a processing feed means from the position corresponding to the outer edge before the wafer is divided into a plurality of pieces to the position corresponding to the inner peripheral side, and the position where the pieces are divided 2. The wafer dividing method according to claim 1, wherein the wafer is retracted in a direction away from the holding surface of the chuck table at a point of time when the wafer is reached.   The recognizing step uses an imaging unit that images the wafer held on the frame via the adhesive film from the front side and an illumination unit that irradiates illumination light that passes through the adhesive film from the back side, Recognizing the shape and position of each divided piece of the wafer by extracting the dividing position by image processing the image signal received by the imaging means of the transmitted light of the illumination light irradiated by the illuminating means The wafer dividing method according to claim 1, wherein:

Images