JP2006032502A - Die bonder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die bonder that can be positioned more accurately. <P>SOLUTION: The deviation amount between the coordinate (X0 and Y0) of the center of a rotating shaft and the center 35 of an XY table is found from the coordinates of the positions of reference chips existing at 0° and 180° positions. The coordinate (Xp and Yp) of the position of an objective chip 41 is decided as the coordinate 42 of the original position of the chip 41 and the deviation amounts 46, 47, and 48 of the chip 41 in the X-, Y-, and θ-directions are respectively decided as ΔX, ΔY, and Δθ. Then the objective coordinate 51 (Xp' and Yp') at the time of correcting the position of the objective chip 41 is calculated based on a calculus 2 using the coordinate 42 (Xp and Yp) of the original position of the chip 41, deviation amounts 46 (ΔX), 47 (ΔY), and 48 (Δθ) of the chip 41 in the X-, Y-, and θ-directions, and the coordinate (X0 and Y0) of the center of the rotating shaft. The center of the chip 41 is positioned to a picking-up position 19 by driving a wafer table 13 in accordance with the objective coordinate 51 (Xp' and Yp'). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a die bonding apparatus that performs chip position correction at the time of pickup.

  Conventionally, when a semiconductor chip is picked up from a wafer in a die bonding apparatus, θ correction of the semiconductor chip is required. For this reason, a rotation mechanism is provided in the bonding head so that θ correction can be performed.

  In such a configuration, since the weight of the bonding head is increased, it is difficult to cope with a semiconductor chip (GaAs) that is easily broken by an impact load.

  Therefore, the inventors have come up with a method for performing θ correction on the wafer side.

  FIG. 8 is a diagram showing an operation by a mechanism in which a rotation axis for θ correction is added to an XY table on which the wafer 101 is placed. As shown in FIG. 8A, the XY direction and θ direction of the semiconductor chip 102 are shown. 4 is configured to move the semiconductor chip 102 to a pickup point 104 by a bonding head by operating an XY table and a rotary table as shown in FIG. 4B. .

  By performing this θ correction on the wafer 101 side using this mechanism, the rotation mechanism on the bonding head side is eliminated, and the impact load can be reduced.

  However, in such a die bonding apparatus, the XY table center 111 and the rotation axis center 112 cannot be accurately aligned, and a deviation occurs. For this reason, even if the XYθ deviation of the semiconductor chip 102 is recognized and corrected, there is a possibility that correct positioning cannot be performed.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a die bonding apparatus capable of performing more accurate positioning.

  In order to solve the above-mentioned problems, the die bonding apparatus of the present invention is a die bonding apparatus that moves a chip to be picked up to a pickup position by a bonding head by driving a wafer in the XY direction and θ direction. A pre-rotation coordinate input means for inputting the position coordinates of the reference chip as pre-rotation coordinates, and a post-rotation coordinate input means for inputting the position coordinates of the reference chip when the wafer is rotated 180 degrees as post-rotation coordinates; Rotation axis center coordinate calculation means for calculating, as the rotation axis center coordinates, the coordinates of the rotation axis center of the wafer from the coordinates before rotation and the coordinates after rotation, the position coordinates of the target chip to be picked up, the position of the target chip The amount of deviation in the XY and θ directions from the pickup position and the rotation axis center coordinates are used. Coordinate calculating means for calculating coordinates for correcting the position of the target chip by calculation.

  That is, when a chip is picked up by this die bonding apparatus, the reference coordinate position of the reference chip is input as the pre-rotation coordinates, and the wafer is rotated 180 degrees to set the reference chip position coordinates as the post-rotation coordinates. input. Then, since the coordinates of the rotation axis center of the wafer can be calculated from the coordinates before rotation and the coordinates after rotation, this is set as the rotation axis center coordinates.

  Then, at the time of pickup, the target chip is calculated by using the position coordinates of the target chip to be picked up, the amount of deviation of the target chip from the pickup position in the XY direction and θ direction, and the rotation axis center coordinates. The coordinates for correcting the position of the chip are calculated.

  As described above, it is necessary to perform the position correction of the target chip by calculating the rotation axis center coordinate of the wafer from the coordinates before rotation and the coordinates after rotation and grasping the rotation center of the wafer. Accurate coordinates are calculated.

  As described above, in the die bonding apparatus of the present invention, it is necessary to perform the position correction of the target chip by calculating the rotation axis center coordinate of the wafer and grasping the rotation center of the wafer. Coordinates can be calculated accurately.

  Thereby, the target chip can be moved to an accurate pickup position by moving the wafer using these coordinates. Accordingly, the rotating mechanism on the bonding head side can be eliminated to reduce the weight of the bonding head, and the impact load applied to the chip from the bonding head can be reduced.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a die bonding apparatus 1 according to the present embodiment. The die bonding apparatus 1 picks up a chip 4 on a wafer sheet 3 stretched on a wafer ring 2 and moves it onto a workpiece. It is a device for transferring and bonding.

  The die bonding apparatus 1 is configured around a control unit 11 having a microcomputer. An XY drive unit 12 is connected to the control unit 11, and the XY drive unit 12 is configured to drive the XY table 14 of the wafer table 13 in accordance with a signal from the control unit 11. A rotation driving unit 15 is connected to the control unit 11, and the rotation driving unit 15 is configured to rotate the rotation table 16 of the wafer table 13 in accordance with a signal from the control unit 11. Yes.

  The wafer table 13 including the XY table 14 and the rotary table 16 is configured to hold the wafer ring 2, and the wafer table 13 is driven by driving the XY table 14 and the rotary table 16. The wafer ring 2 held on the wafer ring 2 is moved, and the wafer 17 provided on the wafer sheet 3 of the wafer ring 2 can be moved in the XY direction and the θ direction. As a result, the wafer 17 is driven in the XY and θ directions so that the chip 4 to be picked up can be moved to the pick-up position 19 by the bonding head 18.

  The control unit 11 includes a camera 21 that acquires an image of the chip 4 on the wafer sheet 3, a display unit 22 that includes a monitor that displays an image acquired by the camera 21, and an input unit that includes a keyboard and a mouse. 23 is connected.

  The operation of the die bonding apparatus 1 according to the present embodiment having the above configuration will be described with reference to the flowchart of FIG.

  That is, when the chip 4 is picked up by the die bonding apparatus 1, as shown in FIG. 3A, the position coordinates (X1) of the reference chip 31 serving as a reference with the rotation axis set to 0 degrees. , Y1), the position A of the point α is input and stored as the pre-rotation coordinates 32 by the operator (S1), and the wafer table 13 is rotated by 180 degrees, as shown in FIG. As shown, the position coordinates (X2, Y2) of the reference chip 31 are inputted as post-rotation coordinates 33 (S2). Next, the coordinates of the rotation axis center 34 of the wafer 17 are calculated from the pre-rotation coordinates 32 and the post-rotation coordinates 33 using the calculation formula 1 in FIG. (X0, Y0) is set (S3), and a deviation (ΔX, ΔY) between the rotation axis center coordinates (X0, Y0) and the XY table center (Table origin) 35 is obtained (S4).

  Next, the position of the target for angle correction is calculated. Briefly described with reference to FIG. 4, the target chip 41 to be picked up is recognized, and the position coordinates (Xp, Yp) of the target chip 41 are recognized. ) As the original position coordinates 42, and the amounts of deviation of the target chip 41 from the pickup position in the XY directions 43, 44 and θ direction 45 are obtained, the X direction deviation amount 46 is ΔX, and the Y direction deviation amount 47 is ΔY. , Θ direction deviation amount 48 is Δθ.

  4A, the original position coordinates (Xp, Yp) of the target chip 41, the X-direction shift amount 46 (ΔX) of the target chip 41, and the Y-direction shift amount. 47 (ΔY), the θ direction deviation amount 48 (Δθ), and the target coordinate 51 (when correcting the position of the target chip 41 by calculation using the calculation formula 2 using the rotation axis center coordinate (X0, Y0)). Xp ′, Yp ′) is calculated, and the wafer table 13 is driven according to the target coordinates 51 (Xp ′, Yp ′) to place the center of the target chip 41 at the pickup position 19.

  More specifically, as shown in FIG. 5, first, the deviation amount between the rotation axis center 34 and the XY table center (Table origin) 35 is set to (ΔX, ΔY), and the original position coordinates (the center point of the target chip 41 ( The angle of Xp, Yp) with respect to the X axis is Δθ1, the angle of the target coordinate 51 (Xp ′, Yp ′) as the center point of the target chip 41 is Δθ2, and the target coordinate 51 as the center point of the target chip 41. After defining the angle (radian) of (Xp ′, Yp ′) with respect to the X axis as Δθ2 ′ (SB1), the target coordinate 51 is centered on the rotation axis center 34 and the circle passing through (Xp ′, Yp ′) The radius R is obtained (SB2). Then, a point (Xp1, Yp1) obtained by moving the original position coordinates (Xp, Yp) by the shift amount (ΔX, ΔY) is calculated (SB3), and whether or not the radius R exceeds 1/1000000. Is determined (SB4).

  At this time, if the radius R does not exceed 1/1000000, Δθ1 is calculated by the formula of asin (0) * 180 / 3.416 (SB5), and the process proceeds to step S7, while the radius When R exceeds 1/1000000, Δθ1 is calculated by the formula of asin (| (Yp1 / R) |) * 180 / 3.416 (SB6), and an accurate value is obtained from the current position area. Shift to angle calculation.

  Here, it is determined whether (Xp1> 0) and (Yp1> = 0) are established (SB7). When established, Δθ1 = asin (0) * 180 / 3.1416 (SB8), and step SB13. Migrate to If (Xp1> 0) and (Yp1> = 0) are not established in step SB7, it is determined whether (Xp1> 0) and (Yp1 <0) are established (SB9).

  At this time, if (Xp1> 0) and (Yp1 <0) are satisfied, Δθ1 = 180 + (Δθ1) is set (SB10), and the process proceeds to step SB13. If not satisfied, (Xp1 < = 0) and (Yp1 <0) (SB11), and (Δθ1) = − (Δθ1) (SB12).

  Next, the angle difference between the target chip 41 at the original position coordinate 42 and the target chip 41 at the target coordinate 51 is obtained as Δθ2 (SB13), and Δθ2 is converted into radians to be Δθ2 ′ (SB14). ), A point (Xp1 ′, Yp1 ′) obtained by rotating the point (Xp1, Yp1) by Δθ by a trigonometric function using Δθ2 ′ is obtained (SB15). Then, the target coordinates 51 (Xp ′, Yp ′) are calculated using this calculation result (SB6), and the target coordinates 51 (Xp ′, Yp ′) are driven through the main routine to drive the wafer table 13. Hand over to

  Thus, the coordinates (X0, Y0) of the rotation axis center 34 of the wafer 17 by the wafer table 13 are calculated, and the position of the target chip 41 is corrected by grasping the rotation axis center 34 of the wafer 17. Therefore, the target coordinates 51 necessary for this purpose can be calculated accurately.

  Accordingly, the target chip 41 can be moved to the accurate pickup position 19 by moving the wafer 17 using the target coordinates 51. Accordingly, the rotating mechanism on the bonding head 18 side can be eliminated, the bonding head 18 can be reduced in weight, and the impact load applied from the bonding head 18 to the chip 4 can be reduced.

It is a block diagram which shows one embodiment of this invention. It is a flowchart which shows the operation | movement which calculates | requires the rotation center coordinate of the wafer table of the embodiment. FIG. 6 is a schematic diagram illustrating an operation for obtaining the rotation center coordinates of the wafer table according to the embodiment, where (a) illustrates a state in which the wafer table is at a 0 degree position, and (b) illustrates the wafer table at a 180 degree position. It is a figure which shows a state. FIG. 6 is a schematic diagram illustrating an operation for obtaining target coordinates of a target chip according to the embodiment, where (a) illustrates a state where the target chip is at the original position coordinates, and (b) illustrates a state where the target chip is at the target coordinates. FIG. It is a flowchart which shows the operation | movement which calculates | requires the target position coordinate of the object chip | tip at the time of performing angle correction of the embodiment. It is a flowchart following FIG. It is a flowchart following FIG. It is explanatory drawing which shows the conventional operation | movement, (a) is a figure which shows the state before correction | amendment of a chip | tip position, (b) is a figure which shows the state after correction | amendment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Die bonding apparatus 4 Chip | tip 11 Control part 17 Wafer 18 Bonding head 19 Pickup position 31 Reference | standard chip 32 Position before rotation 33 Position after rotation 34 Center of rotation axis 41 Target chip 42 Original position coordinate 43 X direction 44 Y direction 45 θ direction 46 X Direction deviation 47 Y direction deviation 48 θ direction deviation 51 Target coordinates

Claims (1)

In a die bonding apparatus that drives a wafer in the XY direction and θ direction to move a chip to be picked up to a pickup position by a bonding head,
A pre-rotation coordinate input means for inputting the position coordinates of the reference chip as a reference as the pre-rotation coordinates;
A post-rotation coordinate input means for inputting the position coordinates of the reference chip when the wafer is rotated 180 degrees as post-rotation coordinates;
Rotation axis center coordinate calculation means for calculating, as the rotation axis center coordinates, the coordinates of the rotation axis center of the wafer from the coordinates before rotation and the coordinates after rotation;
For correcting the position of the target chip by calculation using the position coordinates of the target chip to be picked up, the amount of deviation of the target chip from the pickup position in the XY and θ directions, and the center coordinate of the rotation axis Coordinate calculation means for calculating coordinates;
A die bonding apparatus comprising:

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