JP7580138B2 - Bonding apparatus, bonding method and program - Google Patents

Description

The present invention relates to technology for a bonding device that mounts electronic components on a substrate.

A bonding device uses a bonding tool such as a suction collet to pick up electronic components such as dies from a semiconductor wafer and mount them on the surface of a substrate such as a lead frame. When picking up an electronic component, misalignment may occur between the bonding tool and the electronic component.

In order to mount electronic components at target positions on a board with high precision, a bonding device has been proposed that uses a camera to capture an image of the bonding tool from below, measures the amount of misalignment between the bonding tool and the electronic component, and corrects the position of the bonding tool (see, for example, Patent Document 1). Such a bonding device calculates the movement trajectory of the entire process from the initial position to the target position, and once the amount of misalignment is calculated, it switches from the existing movement trajectory to a movement trajectory toward the corrected target position to perform the position correction.

JP 2012-59933 A

However, it can take time to calculate the amount of deviation from the captured image. If the amount of deviation is calculated when the bonding tool is approaching the target position and decelerating, the movement trajectory cannot be changed in time and the bonding tool moves to the target position and stops there. This results in wasted time from the moment the tool stops until it starts moving again toward the corrected target position.

The present invention was made in consideration of these problems, and aims to provide technology related to a bonding device that can mount electronic components at target positions on a substrate while minimizing wasted time.

A bonding apparatus according to one aspect of the present invention is a bonding apparatus for bonding an electronic component to a substrate, and includes a bonding tool that picks up the electronic component from an initial position and bonds it to a target position on the substrate, a drive unit that moves the bonding tool, and a control unit that periodically updates the coordinates of the bonding tool from a first coordinate to a second coordinate at a predetermined time interval and controls the drive unit to move the bonding tool from the initial position to the target position based on the total amount of movement from the first coordinate to the second coordinate.

According to the present invention, instead of calculating the movement trajectory of the entire process from the initial position to the target position and then moving the bonding tool, the movement trajectory of the small movements in each period is repeatedly calculated and these are connected to move the bonding tool, making it possible to change the target position even during deceleration and to continuously move to the changed target position. This provides technology related to a bonding device that can mount electronic components at the target position on the board while minimizing wasted time.

1 is a cross-sectional view showing an example of a bonding apparatus according to an embodiment of the present invention. 2 is a block diagram showing the relationship of functional components of the bonding apparatus shown in FIG. 1; 2 is a cross-sectional view showing a movement trajectory of a bonding head when the bonding head and an electronic component shown in FIG. 1 are not misaligned. 2 is a cross-sectional view showing a movement locus of the bonding head when the bonding head and the electronic component shown in FIG. 1 are misaligned. 2 is a flowchart showing a bonding method using the bonding apparatus shown in FIG. 1 .

A preferred embodiment of the present invention will be described with reference to the attached drawings. In each drawing, the same reference numerals are used to denote the same or similar configurations. Each configuration will be described in detail below with reference to Figs. 1 to 4. Fig. 1 is a cross-sectional view showing an example of a bonding device 1 according to one embodiment of the present invention.

The bonding apparatus 1 according to one embodiment of the present invention is a die bonder that bonds an electronic component D, such as a die, to a substrate F, such as a lead frame. Bonding an electronic component D to a substrate F includes not only bonding the electronic component D directly to the substrate F, but also stacking and bonding the electronic component D on top of other electronic components that are bonded to the substrate F.

The electronic component D is not limited to a die (semiconductor element) and may be other types of electronic components such as a MEMS chip. When the electronic component D is a die, it may be die-bonded with the active surface facing upward, or may be flip-chip bonded with the active surface facing downward. The substrate F is not limited to a lead frame and may be other types of substrates such as an interposer substrate.

As shown in FIG. 1, the bonding device 1 includes a stage 3 for transporting a substrate F, a bonding tool 2 such as a suction collet attached to a bonding head, and a camera 61 for capturing an image of the bonding tool 2 from below.

The bonding device 1 may further include, as optional components, a wafer cassette lifter that supplies electronic components D fixed to a wafer ring or the like to the bonding head, a frame stack loader that supplies a substrate F to the stage 3, a dispenser that applies an adhesive such as silver paste to the substrate F transported on the stage 3, and an unloader magazine that retrieves the substrate F on which the electronic components D are mounted from the stage 3.

In the following description, the transport direction of the stage 3 along which the substrate F moves is defined as the X-axis direction, the width direction of the stage 3 transverse to the transport direction as the Y-axis direction, and the up-down direction as the Z-axis direction. In the illustrated example, the X-axis, Y-axis, and Z-axis are mutually perpendicular. The bonding head includes a drive unit 5, which will be described later, and uses the bonding tool 2 to pick up an electronic component D located at an initial position (0,0,0) from a wafer ring or the like, and mounts it at a target position ( _Sx , _Sy , _Sz ) on the substrate F to which an adhesive, solder, or the like has been applied.

Figure 2 is a block diagram showing the relationship between the functional components of the bonding apparatus 1 shown in Figure 1. As shown in Figure 2, the bonding apparatus 1 includes a drive unit 5 that moves the bonding tool 2, a control unit 4 that controls the drive unit 5, a measurement unit 6 that measures the amount of misalignment between the bonding tool 2 and the electronic component D, and the like.

The control unit 4 includes a trajectory calculation unit 41 such as a motion controller that calculates the movement trajectory of the bonding tool 2. The control unit 4 may further include other types of control boards. In addition to the camera 61 described above, the measurement unit 6 further includes an image processing unit 62 such as a vision board that processes the image captured by the camera 61 and calculates the amount of deviation between the bonding tool 2 and the electronic component D.

The drive unit 5 includes motors 52X, 52Y, and 52Z that move the bonding tool 2 in the X-axis, Y-axis, and Z-axis directions, and servo amplifiers 51X, 51Y, and 51Z that drive the motors 52X, 52Y, and 52Z in response to commands from the trajectory calculation unit 41. The drive unit 5 may further include a motor that rotates the bonding tool 2 around a rotation axis parallel to the Z-axis, and a servo amplifier that drives the motor.

One of the features is that the trajectory calculation unit 41 periodically updates the coordinates (X, Y, Z) of the destination of the bonding tool 2, and the drive unit 5 sequentially moves the bonding tool 2 to the coordinates given by the trajectory calculation unit 41. In the following description, the coordinates before the update in each cycle may be called the "first coordinates" or "origin coordinates", and the coordinates after the update may be called the "second coordinates" or "destination coordinates". In each cycle, the coordinates before the update and the coordinates after the update may be the same. In that case, the amount of movement in that cycle is zero, and the bonding tool 2 can stay in place without moving.

According to the bonding apparatus 1 configured as above, instead of calculating the movement trajectory of the entire process from the initial position (0,0,0) to the target position ( _Sx , _Sy , _Sz ) and moving the bonding tool 2, the movement trajectory of the minute movement in each period is repeatedly calculated and these are joined together to move the bonding tool 2, so that the target position ( _Sx , _Sy , _Sz ) can be changed even while the bonding tool 2 is decelerating, and it is possible to continuously move to the changed target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ). The electronic component D can be mounted at the target position ( _Sx , _Sy , _Sz ) on the board F while minimizing wasted time.

When the cycle for updating the coordinates (X, Y, Z) of the bonding tool 2 is sufficiently small, the movement trajectory of the bonding tool 2 can be changed more smoothly compared to the case where the movement trajectory of the entire process from the initial position (0, 0, 0) to the target position ( _Sx , _Sy , _Sz ) is output. The cycle for the trajectory calculation unit 41 to update the coordinates is preferably within 400 μsec, for example, and more preferably within 200 μsec.

Figure 3A is a cross-sectional view showing the movement trajectory of the bonding tool 2 when there is no misalignment between the bonding tool 2 and the electronic component D shown in Figure 1, and Figure 3B is a cross-sectional view showing the movement trajectory of the bonding tool 2 when there is misalignment between the bonding tool 2 and the electronic component D shown in Figure 1. When picking up the electronic component D, misalignment may occur between the bonding tool 2 and the electronic component D. When the bonding tool 2 is a suction collet, misalignment in the Z direction is unlikely to occur, so misalignment parallel to the XY plane occurs as shown in Figure 3B.

When the trajectory calculation unit 41 receives the amount of deviation ( _-Xdc , _-Ydc , 0) measured by the measurement unit 6, it adds a correction value corresponding to the amount of deviation ( _-Xdc , _-Ydc , 0) to each of the second coordinates that are periodically updated so as to cancel the amount of deviation ( _-Xdc , _-Ydc , 0) by the sum ( _Xdc , _Ydc , 0) of the added correction values. As a result, as shown in Fig. 3B, the movement trajectory of the bonding tool 2 changes, and even if a positional deviation occurs between the bonding tool 2 and the electronic component D, the electronic component D can be mounted at the target position ( _Sx , _Sy , _Sz ) on the board F.

In the bonding apparatus 1 according to an embodiment of the present invention, the trajectory calculation unit 41 calculates the movement trajectory of the entire process from the initial position (0,0,0) to the target position ( _Sx , _Sy , _Sz ), and when the deviation amount ( _-Xdc , _-Ydc ,0) is calculated, the existing movement trajectory is switched to a movement trajectory toward the corrected target position to perform position correction, but the movement trajectory of the minute movement including the correction value is repeatedly calculated in each period, and the bonding tool 2 is moved by connecting them. Since the addition of the correction value can be started from any of the movement trajectories of many movement trajectories, it becomes possible to move to the corrected target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ) continuously. As shown in FIG. 3B, the movement trajectories before and after the change are smoothly continuous, so that the wasted time can be minimized.

The manner in which the bonding apparatus 1 of one embodiment of the present invention changes the movement trajectory of the bonding tool 2 is not limited to position correction between the bonding tool 2 and the electronic component D. For example, the bonding apparatus 1 may be used in a manner in which the bonding tool 2 starts moving from an initial position toward a rough target position with a swing range, and while the bonding tool 2 is moving, the control unit 4 is notified of the detailed target position from an external device and changes the movement trajectory to a target position different from the target position at the start of the movement.

Figure 4 is a flowchart showing an example of a bonding method according to one embodiment of the present invention, which shows a bonding method (steps S1 to S13) using the bonding apparatus 1 shown in Figure 1. As shown in Figure 4, the bonding method first uses the bonding tool 2 to pick up the electronic component D from the initial position (0,0,0) (step S1).

Then, the coordinates (X, Y, Z) of the bonding tool 2 are periodically updated from the first coordinates to the second coordinates (step S2), and the driving unit 5 moves the bonding tool 2 to the updated coordinates (X, Y, Z) (step S3). Steps S2 to S3 are repeated until the bonding tool 2 reaches the optical axis 61Z of the camera 61 (step S4: No).

When the bonding tool 2 reaches the optical axis 61Z of the camera 61 (step S4: Yes), the camera 61 captures an image of the electronic component D held by the bonding tool 2 (step S5). After capturing the image, the coordinates (X, Y, Z) of the bonding tool 2 are periodically updated from the first coordinates to the second coordinates (step S6), and the driving unit 5 moves the bonding tool 2 to the updated coordinates (X, Y, Z) (step S7).

Steps S6 to S7 are repeated until the image processing unit 62 of the measurement unit 6 measures the amount of deviation ( _-Xdc , _-Ydc , 0) from the captured image (Step S8: No). When the image processing unit 62 measures the amount of deviation ( _-Xdc , _-Ydc , 0) from the captured image (Step S8: Yes), it contacts the control unit 4 of the measurement unit 6.

In the control unit 4 that has received the deviation amount ( _-Xdc , _-Ydc , 0), the trajectory calculation unit 41 periodically updates the first coordinates to the second coordinates (step S9), and then adds a minute correction value according to the deviation amount ( _-Xdc , _-Ydc , 0) to each of the updated second coordinates, thereby gradually correcting and updating the coordinates (X, Y, Z) of the bonding tool 2. The driving unit 5 moves the bonding tool 2 to the updated coordinates (X, Y, Z) (step S11).

Steps S9 to S11 are repeated until the bonding tool 2 reaches the corrected target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ) (Step S12: No). When the bonding tool 2 reaches the corrected target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ) (Step S12: Yes), the bonding tool 2 mounts the electronic component D at the target position ( _Sx , _Sy , _Sz ) on the substrate F (Step S13).

A program according to an embodiment of the present invention causes the bonding apparatus 1 shown in Fig. 1 to execute the bonding method (steps S1 to S13) shown in Fig. 4. The program may be stored in a storage device such as a hard disk drive or flash memory of the bonding apparatus 1, or may be stored in a removable storage medium such as an optical disk, and installed in the storage device of the bonding apparatus 1 by mounting the storage medium in a drive device. According to these techniques related to the bonding apparatus 1 according to an embodiment of the present invention, it is possible to mount an electronic component D at a target position (S _x , S _y , S _z ) on a substrate F while minimizing wasted time.

The above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangements, materials, conditions, shapes, sizes, etc., are not limited to those exemplified, and may be modified as appropriate. Furthermore, configurations shown in different embodiments may be partially substituted or combined.

[Appendix 1]
The bonding apparatus 1 is a bonding apparatus that bonds an electronic component D to a substrate F, and is equipped with a bonding tool 2 that picks up the electronic component D from an initial position (0,0,0) and bonds it to a target position ( _Sx , _Sy , _Sz ) on the substrate F, a drive unit 5 that moves the bonding tool 2, and a control unit 4 that periodically updates the coordinates (X,Y,Z) of the bonding tool 2 from first coordinates to second coordinates at a predetermined time interval, and controls the drive unit 5 to move the bonding tool 2 from the initial position (0,0,0) to the target position ( _Sx , _Sy , _Sz ) based on the total amount of movement from the first coordinates to the second coordinates ( _Sx , _Sy , _Sz ).

According to the above supplementary note 1, instead of calculating the movement trajectory of the entire process from the initial position (0,0,0) to the target position ( _Sx , _Sy , _Sz ) and moving the bonding tool 2, the movement trajectory of the minute movement in each period is repeatedly calculated and these are joined together to move the bonding tool 2, so that the target position ( _Sx , _Sy , _Sz ) can be changed even during deceleration, and movement to the changed target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ) can be continuously performed. It is possible to provide a technology related to a bonding apparatus 1 that can mount an electronic component D at a target position ( _Sx , _Sy , _Sz ) on a substrate F while minimizing wasted time.

[Appendix 2]
In the above Supplementary Note 1, the device may further include a measuring unit 6 that measures the amount of misalignment ( _-Xdc , _-Ydc , 0) between the bonding tool 2 and the electronic component D, and the control unit 4 may add a correction value according to the amount of misalignment ( _-Xdc , _-Ydc , 0) to each of the second coordinates that are periodically updated, and correct the amount of misalignment ( _-Xdc , _-Ydc , 0) based on the sum ( _Xdc , Ydc _, 0) of the added correction values.

[Appendix 7]
The bonding method (steps S1 to S13) includes picking up an electronic component D from an initial position (0,0,0) using a bonding tool 2 (step S1), periodically updating the coordinates (X,Y,Z) of the bonding tool 2 from first coordinates to second coordinates (steps S2, S9, S12), capturing an image of the electronic component D held by the bonding tool 2 (step S5), measuring the amount of deviation between the bonding tool and the electronic component from the captured image (step S8), adding a correction value according to the amount of deviation ( _-Xdc , _-Ydc , 0) to each of the second coordinates that are periodically updated (step S10), and controlling a drive unit 5 that moves the bonding tool 2 to move the bonding tool 2 from the initial position (0,0,0) to the amount of deviation ( _-Xdc , -Ydc, 0 ₎ based on the sum of the amount of movement from the first coordinates to the second coordinates ( _Sx + _Xdc , _Sy + _Ydc , _Sz ). and moving the bonding tool 2 to a corrected target position ( _Sx , _Xdc , _Sy + _Ydc , _Sz ) (step S12), and mounting the electronic component D held by the bonding tool 2 at the target position ( _Sx , _Sy , _Sz ) on the substrate F (step S13).

[Appendix 8]
The program includes steps of: using the bonding tool 2 to pick up the electronic component D from an initial position (0,0,0) (step S1); periodically updating the coordinates (X,Y,Z) of the bonding tool 2 from first coordinates to second coordinates (steps S2, S9, S12); imaging the electronic component D held by the bonding tool 2 (step S5); measuring the amount of deviation between the bonding tool and the electronic component from the captured image (step S8); adding a correction value according to the amount of deviation ( _-Xdc , _-Ydc , 0) to each of the second coordinates that are periodically updated (step S10); and controlling the drive unit 5 that moves the bonding tool 2 to move the bonding tool 2 from the initial position (0,0,0) to a target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ) obtained by correcting the amount of deviation (-Xdc, -Ydc, 0) based on the total amount of movement from the first coordinates to the second coordinates ( _Sx + _Xdc , Sy+ _Ydc , Sz). _The bonding apparatus 1 then moves the bonding tool 2 to _a target position (S _x , S y , S _z ) on the substrate F (step S12), and mounts the electronic component D held by the bonding tool 2 at a _target position (S x , S _y , S _z ) on the substrate F (step S13).

According to the above Supplementary Note 2 and Supplementary Notes 7 and 8, the amount of deviation ( _-Xdc , _-Ydc , 0) between the bonding tool 2 and the electronic component D measured using the measuring unit 6 can be corrected based on the sum ( _Xdc , _Ydc , 0) of the added correction values. Even if a positional deviation occurs between the bonding tool 2 and the electronic component D when picking up the electronic component D, the electronic component D can be mounted with high accuracy at the target position ( _Sx + _Xdc , _Sy + _Ydc , _Sz ) on the board F.

[Appendix 3]
In the above Supplementary Note 2, the measuring unit 6 may further include a camera 61 capable of capturing an image of the electronic component D held by the bonding tool 2, and measure the amount of deviation (-X _dc , -Y _dc , 0) from the captured image.

According to the above supplementary note 3, the amount of deviation (−X _dc , −Y _dc , 0) can be measured with high accuracy from the image captured by the camera 61 in a non-contact manner.

[Appendix 4]
In the above Supplementary Note 2, the sum of the added correction values (X _dc , Y _dc , 0) may be a horizontal movement parallel to the XY plane.

When a suction collet is used for picking up, positional deviation in the Z direction is less likely to occur. According to the above supplementary note 4, this is suitable when the bonding tool 2 is a suction collet. Note that the bonding tool 2 is not limited to a suction collet, and may be a chuck, etc.

[Appendix 5]
In any one of Supplementary Notes 1 to 4 above, the control unit 4 may calculate the second coordinates using the following formulas (1) and (2).

According to the above Supplementary Note 5, the bonding tool 2 can be moved while avoiding obstacles (e.g., the camera 61 and the guide of the stage 3) between the initial position (0,0,0) and the target position ( _Sx , _Sy , _Sz ) along a smooth movement trajectory calculated by a seventh-order equation.

[Appendix 6]
In any one of Supplementary Notes 2 to 4, the control unit 4 may calculate the second coordinate to which the correction value has been added using the following formulas (3) and (4).

According to Supplementary Note 6 above, the correction value added to each of the periodically updated second coordinates is calculated using a seventh-order formula similar to the movement trajectory before correction, so that the movement trajectory in each period to which the correction value is added can be smoothly connected.

1...bonding device, 2...bonding tool, 3...stage, 4...control unit, 5...driving unit, 6...measurement unit, 41...trajectory calculation unit, 51X, 51Y, 51Z...servo amplifier, 52X, 52Y, 52Z...motor, 61...camera, 61Z...optical axis of camera, 62...image processing unit, D...electronic component, F...board.

Claims (7)

A bonding apparatus for bonding an electronic component to a substrate, comprising:
a bonding tool that picks up the electronic component from an initial position and bonds it to a target position on the substrate;
A drive unit that moves the bonding tool;
a control unit that periodically updates coordinates of the bonding tool from first coordinates to second coordinates at a predetermined time interval, and controls the driving unit to move the bonding tool from the initial position to the target position based on a total amount of movement from the first coordinates to the second coordinates;
a measuring unit that measures an amount of misalignment between the bonding tool and the electronic component held by the bonding tool;
Equipped with
the control unit adds a correction value corresponding to the amount of deviation to each of the second coordinates that are periodically updated, and corrects the amount of deviation based on a sum of the added correction values.
Bonding equipment. The measurement unit further includes a camera capable of capturing an image of the electronic component held by the bonding tool, and measures the amount of deviation from the captured image.
2. The bonding apparatus according to claim 1 . The sum of the added correction values is a horizontal movement parallel to the XY plane.
2. The bonding apparatus according to claim 1 . The control unit calculates the second coordinates using the following formulas (1) and (2):
The bonding apparatus according to claim 1 .
The control unit calculates the second coordinate to which the correction value is added by using the following formulas (3) and (4).
The bonding apparatus according to claim 1 .
Picking up the electronic component from an initial position using a bonding tool;
periodically updating coordinates of the bonding tool from first coordinates to second coordinates;
taking an image of the electronic component held by the bonding tool;
measuring an amount of misalignment between the bonding tool and the electronic component held by the bonding tool from the captured image;
adding a correction value corresponding to the amount of deviation to each of the second coordinates that are periodically updated; and
controlling a drive unit that moves the bonding tool, moving the bonding tool from the initial position to a target position where the deviation amount has been corrected based on a sum of the movement amounts from the first coordinates to the second coordinates, and mounting the electronic component held by the bonding tool at the target position on a substrate.
Bonding method. Picking up the electronic component from an initial position using a bonding tool;
periodically updating coordinates of the bonding tool from first coordinates to second coordinates;
taking an image of the electronic component held by the bonding tool;
measuring an amount of misalignment between the bonding tool and the electronic component held by the bonding tool from the captured image;
adding a correction value corresponding to the amount of deviation to each of the second coordinates that are periodically updated; and
a drive unit that moves the bonding tool, and based on a sum of the movement amounts from the first coordinates to the second coordinates, moves the bonding tool from the initial position to a target position where the deviation amount has been corrected, and mounts the electronic component held by the bonding tool at the target position on a substrate;
program.

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