JP2930093B2 - Bonding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bonding method for bonding an electronic component to a substrate, and more particularly, to a bonding method capable of reducing a positioning error between the electronic component and the substrate.

[0002]

2. Description of the Related Art Conventionally, the following methods are known as a bonding method for bonding an electronic component to a substrate. That is, an XY table on which a substrate is placed and movable in XY directions orthogonal to each other in a horizontal plane,
An X-direction motor for moving the XY table in the Y direction; a X-direction motor for moving the XY table in the Y direction;
X-direction linear scale for detecting the amount of movement of the Y table, and Y for detecting the amount of movement of the XY table in the Y direction
A directional linear scale, a bonding tool arranged vertically above and below the XY table and capable of holding and rising and lowering electronic components, and an electronic tool held by the bonding tool in conjunction with the bonding tool. A rotation angle adjustment motor for rotating the component in a horizontal plane, and a rotation angle adjustment motor fixedly provided above the XY table, and XY when the XY table stops at a predetermined first position.
A first camera for photographing a substrate placed on the table from above, and an electronic component fixedly mounted on the XY table and held by the bonding tool when the XY table stops at a predetermined second position A second camera for photographing the camera from below, and a control device for controlling the operation of each of the motors and for inputting the images photographed by the first camera and the second camera. Based on the image input from the computer, the amount of displacement of the substrate with respect to the regular mounting position and the amount of displacement of the electronic component with respect to the regular holding position by the bonding tool are calculated. To position the board below the electronic components held by the bonding tool. Bonding method so that the bonding by pressing the components on a substrate is known. It should be noted that, in addition to the above, a table on which a substrate is
There is also known a device which is capable of moving the bonding tool in the X direction and the bonding tool in the Y direction, and relatively moving the table and the bonding tool in the X and Y directions to position the substrate and the electronic component.

[0003]

By the way, in the above-mentioned conventional method, the displacement amount of the electronic component held by the bonding tool from the normal holding position and the deviation of the electronic component held by the bonding tool from the normal mounting position of the substrate mounted on the XY table are considered. Although the shift amount is a problem, the shift amount between the actual stop position and the regular first and second positions when the XY table is stopped at the first position and the second position is not taken into consideration. Conventionally, although there is a slight positional shift between the regular first position and the second position and the stop position where the XY table is actually stopped, the amount of the shift is determined by moving the substrate to a position below the electronic component. It is not used as a basis for calculating an error in positioning, and there has been a drawback in that the positioning error is increased by that much in the related art. More specifically, conventionally, when the moving resolution of both motors was set to 0.5 μm, the resolution of both linear scales was also set to 0.5 μm, so that the XY table was set to the first position and the second position. When the XY table is moved only once each time and positioned, the XY table moves only a total of two times, and a maximum of 1 μm
Results in a positioning error of In order to reduce such a positioning error, the moving resolution of the X-direction motor and the Y-direction motor and the resolution of both linear scales may be made smaller than before. That is, for example, the moving resolution of both motors may be set to 0.1 μm, and the resolution of both linear scales may be set to 0.1 μm. However, when the moving resolution of both motors is reduced in this way,
There is a disadvantage that the moving speed when moving the XY table in the XY directions becomes slow, and therefore, it takes a long time for positioning. Therefore, an object of the present invention is to improve the positioning accuracy without lowering the positioning speed.

[0004]

In other words, the present invention provides a table on which a substrate is placed and which can be moved in a horizontal direction, and which is disposed vertically above the table so as to hold electronic components. And a rotatable and rotatable bonding tool, an X-direction motor for relatively moving the table and the bonding tool in the X direction of the XY directions orthogonal to each other, and an XY orthogonal to the table and the bonding tool. Motor that moves relatively in the Y direction, a linear scale that detects the relative movement between the table and the bonding tool in the X direction, and a relative scale between the table and the bonding tool in the Y direction. A Y-axis linear scale for detecting the amount of movement, and an electric power held by the bonding tool in conjunction with the bonding tool. A rotation angle adjustment motor for rotating components in a horizontal plane, a first camera for photographing a substrate mounted on the table from above when the table is stopped at a predetermined first position with respect to the bonding tool, A second camera fixed to the table, for photographing the electronic component held by the bonding tool from below when the table stops at a predetermined second position with respect to the bonding tool; And a control device to which the images taken by the first camera and the second camera are input, and the control device controls the normal operation based on the images input from both cameras. Calculate the amount of displacement of the board from the mounting position and the amount of displacement of the electronic component from the proper holding position by the bonding tool so that the positioning error is minimized. The cable and the bonding tool are relatively moved in the X and Y directions to position the substrate below the electronic component held by the bonding tool, and then the bonding tool is lowered from that state, and the electronic component is pressed against and bonded to the substrate. In the bonding method described above, an X-direction linear scale having a resolution higher than the moving resolution of the X-direction motor is employed, and a Y-direction linear scale having a resolution higher than the moving resolution of the Y-direction motor is employed. Detecting the amounts of displacement of the bonding tool and the table from the regular first position when the bonding tool and the table are stopped at the first position on the two linear scales, and moving the bonding tool and the table to the second position. Bonding tool and second for the regular second position when stopped The controller detects the amount of displacement of the table and the two linear scales, and based on the above-described four types of displacement, determines the position below the electronic component held by the bonding tool so that the positioning error is minimized. It is configured to position the substrate at a position.

[0005]

According to this structure, the moving resolution of the X-direction motor and the Y-direction motor is not changed from the conventional one, and a linear scale having a small resolution is adopted. Then, based on four types of shift amounts including the shift amounts between the actual stop position and the regular positions when the table is stopped at the first position and the second position, which have not been considered in the related art. Then, the control device performs the positioning so that the positioning error is minimized. As described above, since the moving resolutions of the X-direction motor and the Y-direction motor do not need to be changed as before, the table and the bonding tool need not be changed.
The moving speed at the time of relative movement in the Y direction does not decrease, and the positioning is performed based on the four types of shift amounts, so that the positioning error can be made smaller than in the past. Therefore, highly accurate positioning can be performed without lowering the positioning speed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1, reference numeral 1 denotes an XY table movable in X and Y directions orthogonal to each other on a horizontal plane.
A mounting table 3 on which the substrate 2 is mounted is mounted at a predetermined position on the upper surface of the XY table 1. The XY table 1 is controlled by an X-direction motor 4 including a servomotor.
, And in the Y-direction by a Y-direction motor 5 composed of a servomotor. In this embodiment, the X-direction motor 4 and the Y-direction motor 5 have a moving resolution of 0.5 μm. The XY table 1 is provided with an X-direction linear scale 6 for detecting the amount of movement when the XY table 1 is moved in the X direction, and the amount of movement when the XY table 1 is moved in the Y direction. Is provided with a Y-direction linear scale 7 for detecting the In the present embodiment, the X-direction linear scale 6 and the Y-direction linear scale 7 have a moving resolution of 0.1 μm. That is, in the present embodiment, both linear scales 6 and 7 are connected to both motors 4 and
A moving resolution higher than the moving resolution of No. 5 is used.
Above the XY table 1, an elevating member 8 is attached to the fixed frame 11 so as to be able to move up and down. A conventionally known bonding tool 12 is attached to the elevating member 8 vertically downward. The elevating member 8 is adapted to be moved up and down in conjunction with the servo motor 13,
Therefore, the bonding tool 12 attached to the elevating member 8 can be moved up and down by rotating the servo motor 13 in the forward and reverse directions. The servo motor 13 has a moving resolution of 0.5 μm. The bonding tool 12 can hold the chip 14 by suction at a lower end portion thereof in a horizontal state, and attaches the substrate 2 on the mounting table 3 to the bonding tool 12.
By lowering the bonding tool 12 holding the chip 14 from the state positioned below the chip 2, the chip 14 can be pressed against and joined to the substrate 2.
The bonding tool 12 is also interlocked with the servomotor 9 disposed vertically downward at the upper end of the main body,
By rotating the servo motor 9 by a required angle, the lower end of the bonding tool 12 is rotated in the forward and reverse directions in the horizontal plane, and the rotational angle position of the chip 14 held at the lower end in the horizontal plane can be adjusted. Has become. A plurality of trays 10 on which a number of chips 14 are placed are placed on the upper surface of the XY table 1. The XY table 1 is moved in the XY directions by a required amount, and then the bonding tool 12 is moved up and down by the required amount. Thereby, one chip 14 in the tray 10 is held by suction. On the other hand, the substrate 2 is mounted on a predetermined position of the mounting table 3 manually or by a transport device (not shown). At a predetermined position above the XY table 1, a first camera 15 vertically fixed downward is fixedly provided. When the XY table 1 is moved and the substrate 2 on the mounting table 3 stops at a first position where it stops below the first camera 15, the first camera 15 moves the substrate 2 on the mounting table 3.
Is mounted, and the captured image of the substrate 2 is input to the control device 16. The second position is located at a predetermined position on the upper surface of the XY table 1.
The camera 17 is mounted vertically upward. Then, the second camera 1 is positioned below the bonding tool 12.
When the XY table 1 stops at the second position where the position 7 is located, the second camera 17 takes an image of the holding state of the chip 14 by the bonding tool 12, and the image is taken by the controller 1
6 is input. Each of the above motors 4,
The operations of 5, 9, and 13 are controlled by the control device 16, and in this embodiment, the control device 16
The substrate 2 is positioned below the chip 14 held by the bonding tool 12 as follows. That is, as shown in FIG. 1, the substrate 2 is placed at a predetermined position on the mounting table 3 and the chip 14 is sucked and held at the lower end of the bonding tool 12, and as shown in FIG. The control device 16 operates the X-direction motor 4 and the Y-direction motor 5 to control the control device 16 in advance.
The XY table 1 is moved to and stopped at the first position input in step S1 (S1). When the XY table 1 is located at the first position, the mounting table 3 is located immediately below the first camera 15.
The upper substrate 2 stops. Here, the XY table 1
There is a slight shift between the first position where the stop has occurred and the normal first position. In the present embodiment, this deviation amount, which has been neglected conventionally, is used as data for positioning. That is, as described above, the moving resolution of the X direction motor 4 and the Y direction motor 5 is 0.5 μm,
On the other hand, since the resolution of the X-direction linear scale 6 and the Y-direction linear scale 7 is 0.1 μm,
The displacement amount in the X and Y directions with respect to the position is detected by the two linear scales 6 and 7 in units of 0.1 μm and input to the control device 16. Here, for example, if the shift amount in the X direction is 0.3 μm and the shift amount in the Y direction is 0.3 μm, the shift amount in the XY direction detected by both linear scales 6 and 7 is as shown in FIG. Is input to the first storage unit 16a of the control device 16 via the counter 21, and the first
The storage unit 16a stores the shift amount in the XY directions (S
2). Next, when the XY table 1 actually stops at the first position as described above, the mounting state of the substrate 2 on the mounting table 3 is photographed by the first camera 15, and the image is stored in the substrate image storage of the control device 16. The data is input to the unit 16b (FIG. 3) and stored (S3). Next, the control device 16 operates the X-direction motor 4 and the Y-direction motor 5 again to move and stop the XY table 1 to the second position previously input to the control device 16 (S4). When the XY table 1 is located at the second position, the second camera 17 provided on the XY table 1 is located immediately below the bonding tool 12. Here, a slight shift occurs between the second position where the XY table 1 is actually stopped and the normal second position.
In the present embodiment, this deviation amount, which has been neglected in the past, is used as data for positioning. The deviation between the second position where the XY table 1 is actually stopped and the normal second position is detected by the linear scales 6 and 7 in units of 0.1 μm and input to the control device 16. Here, for example, assuming that the shift amount in the X direction is 0.2 μm and the shift amount in the Y direction is 0.2 μm, as shown in FIG. The deviation amount of the counter 2
The data is input to the second storage unit 16c of the control device 16 via the control unit 1, and the second storage unit 16c stores the shift amount in the XY directions (S5). Next, as described above, when the XY table 1 actually stops at the second position, the holding state of the chip 14 held by the bonding tool 12 is photographed by the second camera 17 provided on the XY table 1, and the image is taken. Is input to and stored in the chip image storage unit 16d of the control device 16 (S6). Thereafter, the operation unit 16e of the control device 16
In order to position the substrate 2 at an optimum position below the chip 14 held by the bonding tool 12 based on the four types of shift amounts stored in the respective portions 16a to 16d, the XY direction and the rotation angle The position where the error is minimized is calculated (S7). In this way, the control device 16
Is calculated by the calculation unit 16e in the XY directions and the rotation angle, the control unit 16
5 and 9 are operated, and X reaches the position determined by the operation unit 16e.
The Y table 1 is moved, and the bonding tool 12 is rotated by the rotation angle deviation amount (S8). Here, if the control unit 16 determines that it is not positioned at the position determined by the calculation unit 16e based on the movement amount of the XY table 1 detected by the two linear scales 6 and 7, the control unit 16 continues. The XY table 1 is moved to the position determined by the calculation unit 16e by rotating each of the motors 4, 5, and 9 by a required amount. As a result, the substrate 2 is positioned below the chip 14 held by the bonding tool 12 such that an error is minimized.
Has been positioned (S9). After the positioning is completed as described above, thereafter, the control device 16 operates the motor 13 to operate the bonding tool 1 as in the related art.
2 is lowered by a predetermined amount, so that the chip 14 is pressed against and joined to the substrate 2. As described above, according to the present embodiment, not only the displacement amount of the mounting position of the substrate 2 photographed by the first camera 15 and the displacement amount of the holding position of the chip 14 photographed by the second camera 17, but also The amount of deviation from the normal position when the XY table 1 is actually stopped at the ignored first and second positions is detected, and the error is minimized based on these four types of deviation. Positioning. Therefore, X is applied to the first position and the second position.
Compared with the conventional case where the deviation amount between the actual stop position and the normal position when the Y table 1 is positioned is ignored, the positioning error can be reduced, and the positioning accuracy can be improved. it can. On the other hand, since the motors 4 and 5 for moving the XY table 1 can have the same moving resolution as the conventional one, the moving speed of the XY table 1 can be improved despite the improvement of the positioning accuracy. It does not decline. In contrast to the above-described embodiment, conventionally, the moving resolution of both motors XY and the resolution of both linear scales 6 and 7 are the same.
When the XY table 1 is stopped at the position and the second position, the XY table 1 is treated as being stopped at the regular first and second positions. For this reason, conventionally, the displacement amount of the mounting position of the substrate 2 photographed by the first camera 15 at the first position and the displacement amount of the holding position of the chip 14 photographed by the second camera 17 at the second position are conventionally determined. In addition, the control device 16 calculates the amount of movement in the XY directions required for positioning.
As described above, conventionally, when the XY table is actually stopped at the first position and the second position, the regular first position and the second
Since the amount of displacement with respect to the position has not been taken into consideration, the positioning error between the chip 14 and the substrate 2 in the XY directions at the end of positioning has been increased accordingly. Second Embodiment FIGS. 4 to 6 show a second embodiment of the present invention. In the first embodiment, the XY table 1 itself moves in the XY directions. In the second embodiment, the table 1 moves only in the Y direction. 8 can be moved in the X direction. The frame 11 is moved by an X-direction motor 4 ′ associated therewith, and the X-direction linear scale 6 ′ is provided in the longitudinal direction of the frame 11. Other configurations are the same as those of the first embodiment described above, and the members corresponding to those of the first embodiment are denoted by the same reference numerals. In the second embodiment having such a configuration, the control device 16 positions the substrate 2 and the chip 14 as follows. That is, as shown in FIG. 4, the substrate 2 is placed at a predetermined position on the mounting table 3 and the chip 14 is sucked and held at the lower end of the bonding tool 12. Apparatus 1
6 operates the X-direction motor 4 'and the Y-direction motor 5 to move and stop the table 1 and the bonding tool 12 to the first position previously input to the controller 16 (S1'). As described above, when the table 1 and the bonding tool 12 are located at the first position, the substrate 2 on the mounting table 3 stops immediately below the first camera 15.
Here, the table 1 and the bonding tool 1 are actually
There is a slight shift between the first position where 2 has stopped and the normal first position. Then, as shown in FIG. 6, the shift amount in the X and Y directions detected by the two linear scales 6 ′ and 7 is transmitted to the first storage unit 1 of the control device 16 via the counter 21.
The first storage unit 16a stores the shift amount in the XY directions (S2). Next, as described above, when the table 1 and the bonding tool 12 are actually stopped at the first position, the mounting state of the substrate 2 on the mounting table 3 is photographed by the first camera 15, and the image is displayed on the control device 16. It is input to and stored in the board image storage unit 16b (FIG. 6) (S3). Next, the control device 16 operates the X-direction motor 4 ′ and the Y-direction motor 5 again to control the control device 16 in advance.
The table 1 and the bonding tool 12 are moved to and stopped at the second position input in step S4 '(S4').
When the table 1 and the bonding tool 12 are located at the second position, the second camera 17 provided on the table 1 is located immediately below the bonding tool 12. here,
A slight shift occurs between the second position where the table 1 and the bonding tool 12 are actually stopped and the normal second position. Then, as shown in FIG. 6, the shift amount in the XY directions with respect to the second position detected by the two linear scales 6 ′ and 7 is input to the second storage unit 16 c of the control device 16 via the counter 21, 2 storage unit 16c stores the X
The shift amount in the Y direction is stored (S5). Next, as described above, when the table 1 and the bonding tool 12 actually stop at the second position, the holding state of the chip 14 held by the bonding tool 12 is photographed by the second camera 17 provided on the table 1, The image is displayed on the control device 16
Is input to and stored in the chip image storage unit 16d (S6). Thereafter, the calculation unit 16e of the control device 16 determines the chip 14 held by the bonding tool 12 based on the four types of shift amounts stored in the respective units 16a to 16d.
In order to position the substrate 2 at an optimal position below the position, the position where the error in the XY directions and the rotation angle is minimized is calculated (S7 '). In this way, when the calculation unit 16e of the control device 16 determines the position where the error between the XY directions and the rotation angle is minimized, the control device 16
5 and 9, the table 1 and the bonding tool 12 are moved to the position determined by the calculation unit 16e, and the bonding tool 12 is moved by the rotation angle deviation.
Is rotated (S8 '). Here, when the control device 16 determines that the arithmetic unit 16e is not positioned at the calculated position based on the movement amounts of the table 1 and the bonding tool 12 detected by the linear scales 6 and 7, Subsequently, the motors 4 ', 5, 9 are rotated by a required amount to move the table 1 and the bonding tool 12 to the position determined by the calculation unit 16e. As a result, the substrate 2 is positioned below the chip 14 held by the bonding tool 12 so as to minimize the error (S2).
9). In such a second embodiment, the first position,
Since the amount of deviation between the actual stop position and the normal stop position when the table 1 and the bonding tool 12 are moved to the second position is used as data for positioning,
As in the first embodiment, high-precision positioning can be performed without lowering the positioning speed. In each of the above-described embodiments, both the cameras 15 and 17 move the substrate 2 and the chip 14 to one. Although the image is shot only once, as shown by the imaginary line in FIG. 7, two predetermined images may be shot on the substrate 2 and the chip 14, respectively. In this case, S2 and S3 in FIGS. 2 and 5 are repeated twice, and S5 and S6 are
It will be repeated times. Thus, both cameras 15, 17
By photographing two predetermined locations, the positioning accuracy can be further improved.

[0007]

As described above, according to the present invention, it is possible to obtain an effect that highly accurate positioning can be performed without reducing the positioning speed.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing one embodiment of the present invention.

FIG. 2 is a view showing an operation process by the control device shown in FIG. 1;

FIG. 3 is a configuration diagram showing a relationship between the control device shown in FIG. 1 and other components.

FIG. 4 is an overall perspective view showing another embodiment of the present invention.

FIG. 5 is a view showing an operation process by the control device shown in FIG. 4;

6 is a configuration diagram showing the relationship between the control device shown in FIG. 4 and other components.

FIG. 7 is a plan view showing different photographing positions when the substrate 2 is photographed by the first camera 15.

[Explanation of symbols]

Reference Signs List 1 XY table (table) 2 Board 4 X-direction motor 4 'X-direction motor 5 Y-direction motor 6 X-direction linear scale 6' X-direction linear scale 7 Y-direction linear scale 9 Motor 12 Bonding tool 13 Motor 14 Chip (electronic component) 15 First camera 16 Control device 17 Second camera

Claims (2)

(57) [Claims] 1. A table on which a substrate is mounted and which can be moved in a horizontal direction, and a bonding table which is disposed vertically above the table so as to be vertically lower and rotatable while holding the electronic components. A tool, an X-direction motor for relatively moving the table and the bonding tool in the X direction in the mutually orthogonal XY directions, and a Y direction for relatively moving the table and the bonding tool in the Y direction in the mutually orthogonal XY directions A motor, an X-direction linear scale for detecting a relative movement amount between the table and the bonding tool in the X direction, and a Y-direction linear scale for detecting a relative movement amount between the table and the bonding tool in the Y direction. A rotation angle for rotating an electronic component held by the bonding tool in a horizontal plane in conjunction with the bonding tool An adjustment motor and a first image pickup device for photographing the substrate placed on the table from above when the table is stopped at a first position predetermined with respect to the bonding tool.
A camera and a second camera fixedly mounted on the table and for photographing the electronic component held by the bonding tool from below when the table stops at a predetermined second position with respect to the bonding tool. A control device that controls the operation of each of the motors, and to which images captured by the first camera and the second camera are input. The control device is configured based on the images input from both cameras. Calculate the amount of displacement of the substrate with respect to the regular mounting position and the amount of displacement of the electronic component with respect to the regular holding position by the bonding tool, and move the table and the bonding tool relatively in the X and Y directions so as to minimize the positioning error. , Positioning the substrate at a position below the electronic component held by the bonding tool, and lowering the bonding tool from that state, In a bonding method in which an electronic component is pressed and bonded to a substrate, an X-direction linear scale having a resolution higher than the moving resolution of the X-direction motor is adopted, and a resolution higher than the moving resolution of the Y-direction motor is adopted. The Y-direction linear scale provided with is used, and when the bonding tool and the table are stopped at the first position, the amount of displacement of the bonding tool and the table with respect to the regular first position is detected by the two linear scales. The regular second when the bonding tool and the table are stopped at the second position.
The amount of displacement of the bonding tool and the table with respect to the position is detected by the two linear scales, and the control device holds the bonding tool based on the above four types of displacement so that the positioning error is minimized. A bonding method, wherein a substrate is positioned below an electronic component. 2. The electronic device according to claim 1, wherein the first camera photographs two predetermined locations on the substrate, and the second camera photographs two predetermined locations on the electronic component. Bonding method.