JP5431973B2 - Split method - Google Patents

Description

  The present invention relates to a dividing method for holding a plurality of workpieces in a holding unit and dividing the workpiece.

  At the time of division processing in which a plate-like workpiece such as a semiconductor wafer is divided into individual chips, the workpiece is attached to a holding tape and integrated with an annular frame attached to the peripheral edge of the holding tape. Then, the workpiece supported by the frame via the holding tape is held by the chuck table, and the position of the workpiece to be processed is imaged and detected in that state, and the detected position is detected by a cutting blade or laser beam. It is divided into individual chips by receiving an action such as.

  Even when a workpiece such as a small package substrate is cut using a cutting device, the small workpiece is adhered to the holding tape and integrated with the annular frame, but is described in Patent Document 1. Thus, in order to ensure productivity, a predetermined number of workpieces are adhered to a predetermined position of one holding tape and integrated with one annular frame, and a plurality of workpieces are integrated into one annular frame. And the workpiece set integrated. Then, the workpiece set is held on a chuck table, and a plurality of workpieces are cut. In this case, the position coordinate value of each workpiece is input to the storage means in the apparatus in advance, and the optical detection means is sequentially positioned with respect to each workpiece based on the position coordinate value. , Alignment to detect the line to be divided is performed.

JP 2001-196328 A

  However, if the workpiece is integrated with one annular frame for each predetermined number of lots, a set of workpieces less than the predetermined number is finally generated. For example, when it is desired to integrate the predetermined number of sheets into four, even if there is a set of workpieces attached to the holding tape, for example, only three sheets are aligned according to the stored contents of the storage means. Since it is performed on the premise that there is a workpiece, alignment is attempted even at a position where the workpiece is not actually present, and as a result, it is not possible to detect a division planned line for that portion. For this reason, the alignment error message is warned and the operation of the machine is stopped, and there is a problem that the operator has to deal with it every time and the productivity is lowered. Since a set of workpieces that is less than the predetermined number is randomly generated, even if only the workpiece set is machined separately, the work becomes complicated and productivity is similarly reduced.

  The present invention has been made in view of the above-mentioned facts, and a main technical problem thereof is a workpiece that constitutes a workpiece set in which a workpiece smaller than a predetermined number is integrated with one annular frame. Even in the case of cutting the machine, it is possible to prevent the machine from being stopped due to an alignment error or the like due to the absence of a workpiece at a predetermined position, and to improve the productivity of divided machining.

  In the present invention, two or more predetermined number of workpieces are arranged at predetermined positions via a holding tape, and a workpiece set integrated with one annular frame is held by the holding means and held by the holding means. Based on the position coordinate value of each predetermined position and the size information and thickness information of the workpiece that are previously stored in the storage means in the state, the position of the division line formed on the surface of each workpiece is optically determined. The present invention relates to a dividing method that is detected by a detecting means and divides along each planned dividing line for each workpiece, and an optical detecting means is sequentially placed above each workpiece in the workpiece set held by the holding means. Positioning and auto-focusing the optical detection means with a predetermined focus stroke based on the size information and thickness information of the work piece, it is determined that there is a work piece when the surface of the work piece is in focus. A workpiece presence / absence storing step for storing the presence / absence of the workpiece in the storage means for each predetermined position, and each workpiece at a predetermined position determined to have a workpiece after the workpiece presence / absence storing step. Alignment process for detecting the division line to be cut and acquiring its position information and storing it in the storage means for each workpiece, and each workpiece at a predetermined position determined to have the workpiece And a dividing step of dividing each workpiece based on the position information of the scheduled division lines.

  The present invention provides an alignment operation for each workpiece at each predetermined position, even when a workpiece set in which a smaller number of workpieces are integrated with one annular frame is an object to be divided. By performing the workpiece presence / absence storage unit that stores in the storage unit whether or not there is a workpiece at each predetermined position, the alignment error due to the absence of the workpiece at the predetermined position is performed. Can prevent the machine from stopping and improve productivity.

It is a perspective view which shows an example of the cutting device used for the division | segmentation process of a workpiece. It is explanatory drawing which shows the structure of an optical detection means, a control means, and a memory | storage means. It is a top view which shows the positional relationship of the objective lens of an optical detection means, and a cutting blade. It is a top view which shows the 1st example of a workpiece set. It is a top view which shows the 2nd example of a workpiece set. It is explanatory drawing which shows an example of a workpiece presence / absence table.

  A cutting apparatus 1 shown in FIG. 1 is a kind of apparatus that divides a workpiece, and holds the workpiece so that it can move in the horizontal direction (X-axis direction in FIG. 1) and can rotate. A holding means 2 having a surface 20 and two cutting means 3a and 3b for cutting the workpiece held by the holding means 2 are provided.

  The holding means 2 is driven by the feed mechanism 21 and is movable in the X-axis direction. The feed mechanism 21 includes a ball screw 210 extending in the X-axis direction, and a pair of guide rails 211 arranged in parallel to the ball screw 210. A motor 212 that rotates the ball screw 210 and a moving base that moves in the X-axis direction by being guided by the guide rail 211 by the rotation of the ball screw 210 when the inner nut is screwed into the ball screw 210 and the lower part is in sliding contact with the guide rail 211 And a table 213. The holding means 2 moves in the X axis direction together with the moving base 213.

  The cutting means 3a and 3b are arranged facing each other. Since the constituent elements of the cutting means 3a and 3b are configured in the same manner, a description will be given with a common reference numeral. The cutting means 3a and 3b are in a direction orthogonal to the horizontal direction with respect to the moving direction of the holding means 2 ( A spindle 30 having a rotation axis in the Y-axis direction in FIG. 1, a housing 31 that rotatably supports the spindle 30, and a cutting blade 32 attached to the tip thereof.

  The two cutting means 3a and 3b are driven by the first feeding means 4a and the second feeding means 4b, respectively, and can move in the Y-axis direction. Since the first feeding means 4a and the second feeding means 4b are configured in the same manner, the first feeding means 4a and the second feeding means 4b are arranged in the Y-axis direction. A ball screw 40 having an axial center, a pair of guide rails 41 arranged in parallel to the ball screw 40, a pulse motor 42 for rotating the ball screw 40, an internal nut screwed into the ball screw 40, and a side portion thereof as a guide rail The movable plate 43 is slidably in contact with 41, and an elevating mechanism 44 that elevates and lowers the cutting means 3a and 3b. The elevating mechanism 44 includes a support portion 440 fixed to the housing 31 and a motor 441 that drives the support portion 440 to move up and down. A linear scale 45 is disposed in parallel with the ball screw 40, and the positions of the two cutting means 3 a and 3 b can be grasped by the linear scale 45.

  Optical detection means 5a and 5b are fixed to the side portions of the housing 31, respectively. As shown in FIG. 2, since the optical detection means 5a and 5b are configured in the same manner, the optical detection means 5a and 5b are provided with a lift unit 50 that can be moved up and down. Yes. The elevating unit 50 includes an objective lens 500, and an imaging unit 51 is disposed on the optical axis. The imaging unit 51 is connected to the image processing unit 52 and can perform processing on image information output from the imaging unit 51.

  The optical detection unit 5 is connected to the control unit 6, and the operations of the lifting unit 50 and the image processing unit 52 are controlled by the control unit 6. The control means 6 is connected to the storage means 7 and can control the optical detection means 5 with reference to information stored in the storage means 7.

  As shown in FIG. 3, the objective lens 500 is formed with a reference line 500a that is a straight line in the X-axis direction passing through the center thereof, and the blade portion 320 of the cutting blade 32 is positioned on an extension line of the reference line 500a. Adjustments have been made in advance.

  As shown in FIG. 4, two or more predetermined number of workpieces W1 (four in the example of FIG. 4) adhered to one holding tape T as a general rule are divided by cutting. W2, W3, and W4, and an annular frame F is attached to the peripheral edge of the holding tape T. In this manner, a predetermined number of workpieces integrated with the annular frame F via the holding tape T is referred to as a complete workpiece set 10. Each workpiece is provided with a division line S vertically and horizontally.

  On the other hand, if the total number of workpieces for each lot is not a multiple of the predetermined number, for example, as shown in FIG. 5, three workpieces W1, W2, and W3 are attached, and the workpieces are filled to the predetermined number. Some are not. Such workpieces are also subject to division. A work piece in which a work piece less than the predetermined number is integrated with the annular frame F via the holding tape T is referred to as an incomplete work piece set 11. The complete workpiece set 10 and the incomplete workpiece set 11 are collectively referred to as a workpiece set.

  Next, the operation of the cutting device 1 when the workpieces constituting the complete workpiece set 10 and the incomplete workpiece set 11 are cut and divided into individual chips using the cutting device 1. explain.

  The four workpieces constituting the workpiece set are attached to predetermined positions on the holding tape T by a tape mounter. Regardless of whether the workpiece is a complete workpiece set 10 or an incomplete workpiece set 11, the coordinates of the upper left corners A, B, C, and D of the positions where each workpiece can exist ( x1, y1), (x2, y2), (x3, y3), (x4, y4) are stored in advance in the storage means 6 as predetermined positions. In addition, size information (information on the length of each side) and thickness information of each workpiece are also stored in the storage unit 6. 4 and 5, the coordinate origin O is the center of the tape T, but the origin may be taken anywhere. Moreover, you may identify how the coordinate information of the predetermined position regarding the attachment position of a workpiece is how.

(1) Workpiece presence / absence storage step When each work piece constituting the complete work piece set 10 shown in FIG. 4 or the incomplete work piece set 11 shown in FIG. 5 is to be cut, FIG. The workpiece set is held by the holding means 2 shown in FIG. 5 and the workpiece set is positioned below the optical detection means 5a and 5b by the movement of the holding means 10 in the X-axis direction. And before detecting the division | segmentation scheduled line S which should be cut, the optical detection means 5a and 5b are each located in the arbitrary positions above each workpiece. Here, an arbitrary position above each workpiece can be obtained from the position coordinate value of each predetermined position stored in the storage means 7 and the size of the workpiece. Specifically, it is obtained by adding a value smaller than the length information of each side stored in the storage means 6 to the coordinates of A, B, C, and D. For example, if the size of each workpiece is 100 mm both vertically and horizontally, for the workpiece W1, the optical axis of the objective lens 500 is located at a position less than 100 mm from the point A in the + X direction and the −Y direction, respectively. If positioned, the optical detection means 5a is positioned above the workpiece W1. Actually, as shown in FIG. 5, it is desirable to place the optical detection means 5a, 5b above the vicinity of the center of each workpiece. For the workpieces W2, W3, and W4, arbitrary positions can be sequentially obtained by the same method. Since the cutting apparatus 1 includes two optical detection means 5a and 5b, it is possible to obtain arbitrary positions of information on the two workpieces by operating them in parallel.

  Next, with the optical detection means 5a positioned above the workpiece W1, the elevation unit 50 is raised and lowered under the control of the control means 6, so that the surface of the workpiece W1 is focused on the surface by autofocus. Match. The Z coordinate of the holding surface 20 of the chuck table 2 shown in FIG. 2 is recognized by the control means 6, and the thickness information of the holding tape T and each workpiece is also stored in the storage means 7. 6, a predetermined focus stroke of the optical detection means 5 a for focusing can be obtained by adding the values of the thickness of the holding tape T and the workpiece to the Z coordinate of the holding surface 20. Therefore, if the lifting / lowering part 50 is driven according to the focus stroke and the surface of the workpiece W1 can be reliably focused, the control means 6 allows the workpiece to be processed in the focus area where the focus is achieved. Judge that there is. On the other hand, when focus is not achieved under a predetermined focus stroke, the control means 6 determines that there is no workpiece at that position. Auto-focusing is performed in the image processing unit 52 by, for example, taking the sum of the differences between adjacent pixels in the imaged region and setting the position where the sum is the largest as the focal point.

  By making such a determination sequentially for all four workpieces while operating the two optical detection means 5a and 5b in parallel, the complete workpiece set 10 shown in FIG. The control means 6 determines that the autofocus has been completed for the workpieces W1, W2, W3, and W4, and these four (predetermined number of) workpieces have been adhered to the tape T. 7 is stored. On the other hand, when the autofocus is completed in the focus areas 101, 102, and 103 but the autofocus is not performed in the focus area 104, as in the incomplete workpiece set 11 shown in FIG. The control unit 6 determines that there is no workpiece in the storage unit 7 and stores the fact in the storage unit 7. For example, as shown in FIG. 6, the area of the workpiece presence / absence table is secured in the storage means 7, and the presence / absence information of the workpiece is stored in correspondence with each predetermined position.

(2) Alignment process Next, the division | segmentation scheduled line which should be cut is detected about the workpiece of the predetermined position judged to exist in the workpiece presence / absence memory | storage process based on the information of a workpiece presence / absence table. Such detection is based on the coordinate values of A, B, C, D stored in the storage means 7 and the size information of each work piece, and optical detection means above the work piece determined to be present. The objective lenses 500 of 5a and 5b are respectively positioned, autofocusing is performed based on the thickness information stored in the storage means 7, and the optical detection means 5 is moved while sequentially acquiring images by the imaging section 51, and the image processing section In 52, pattern matching is performed between the acquired image information and the image of the planned division line S stored in advance in the storage unit 7. As shown in FIG. 3, since the adjustment is made in advance so that the blade part 320 of the cutting blade 32 is positioned on the extended line of the reference line 500a, the division schedule is made when the reference line 500a and the division planned line S coincide. The line S is detected and it is determined that the Y-axis direction alignment with the cutting blade S is made, and the control means 6 stops the movement of the optical detection means 5. Then, the XY coordinate information of the optical detection means 5 is stored in the storage means 7 as the position information of the division planned line. Similarly, the position information is acquired for the other division lines, and the coordinate information of all the division lines is stored in the storage unit 7. In addition, position information is acquired for only one division planned line in one direction for one workpiece, and at the time of subsequent cutting, the interval between the division planned lines is stored in advance in the storage means 7 and is sent at intervals. However, cutting may be performed.

  Further, the position information of the division planned line is similarly acquired for other workpieces determined to be present in the workpiece presence / absence storage step, and the XY coordinate information of the detected division planned line is stored as alignment information. 7 is stored. In this way, since this process is performed only for the workpieces that are determined to be in the workpiece presence / absence storing step, the division schedule line cannot be detected, and the apparatus does not stop due to an error.

(3) Dividing Step When the alignment step is completed in this way, the control means 6 reads the position information of the planned dividing line stored in the storage means 7 for each workpiece determined to be present, and the cutting blade 32 is set at the coordinates. Positioning and moving the holding table 2 in the X direction, the rotating cutting blade 32 is cut into the division line S and cutting is performed along the division line S. By operating the two cutting means 3a and 3b in parallel, two workpieces can be cut in parallel. When all the planned division lines in one direction of the workpiece are cut, and then the holding table 2 is rotated 90 degrees and then the same cutting is performed, the workpiece is divided into individual chips. The same division is performed for other workpieces that are determined to be present.

  In this way, the alignment process is performed only on the workpieces determined to be in the workpiece presence / absence storage step in the alignment step, and the workpieces determined to be in the workpiece presence / absence storage step also in the division step. Since the division is performed only for, the division can be performed with high productivity.

  In the above example, the case where the division processing is performed using the cutting device has been described. However, the present invention can also be applied to a laser processing device that irradiates a laser beam to a division planned line detected by alignment.

1: Cutting device 2: Holding means 20: Holding surface 21: Feed mechanism 210: Ball screw 211: Guide rail 212: Motor 213: Moving base 3a, 3b: Cutting means 30: Spindle 31: Housing 32: Cutting blade 320: Blade Portion 4a: First feeding means 4b: Second feeding means 40: Ball screw 41: Guide rail 42: Pulse motor 43: Movable plate 44: Lifting mechanism 440: Support portion 441: Motor
45: Linear scale 5: Optical detection means 50: Elevating part 500: Objective lens 500a: Reference line 51: Imaging part 52: Image processing part 6: Control means 7: Storage means 10: Complete workpiece set 11: Incomplete Workpiece set W1, W2, W3, W4: Workpiece T: Holding tape F: Ring frame S: Scheduled division lines 101, 102, 103, 104: Focus area

Claims (1)

Two or more predetermined number of workpieces are arranged at predetermined positions via the holding tape, and the workpiece set integrated with one annular frame is held by the holding means, and in a state of being held by the holding means in advance Based on the position coordinate value of each predetermined position stored in the storage means and the size information and thickness information of the work piece, the optical detection means detects the position of the division line formed on the surface of each work piece. And a dividing method for dividing the workpiece along the planned dividing line for each workpiece,
The optical detection means is sequentially positioned above each work piece of the work piece set held by the holding means, and at a predetermined focus stroke based on the size information and the thickness information of the work piece. When the optical detection means is autofocused and the surface of the workpiece is in focus, it is determined that the workpiece is present, and the presence or absence of the workpiece is determined for each predetermined position. A workpiece presence / absence storing step stored in
After each workpiece presence / absence storing step, for each workpiece at the predetermined position determined to have the workpiece, the division line to be cut is detected and the position information is acquired to obtain each workpiece. An alignment step for storing each object in the storage means;
A dividing step of dividing each workpiece based on position information of a division-scheduled line of each workpiece at the predetermined position determined to have the workpiece;
A division method consisting of

Images