JP2004022745A - Conductive ball-removing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely remove unwanted conductive balls by obtaining the inclination of a ball holding surface of a mount head beforehand, before the operation of a conductive ball mounter and keep the distance between the ball-holding face and a suction nozzle as a removing means to be constant according to the removal position of the unwanted conductive ball. <P>SOLUTION: The conductive ball-removing device is provided with a gap detecting means, that relatively moves close to the ball-holding surface to detect a specified limit gap between the surface and itself. According to the relative approached quantity between the ball-holding surface and the distance detection means, the relative vertically moved quantity between the mounting head and the removing means, when the specified moving distance is determined at the time of removing unwanted conductive balls. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an improvement of a conductive ball mounting device, and mainly focuses on a removing means for removing unnecessary conductive balls held on a ball holding surface of a mount head and a determination of a lifting amount of the mount head. It was developed.
[0002]
[Prior art]
Conventionally, in a conductive ball mounting device, a method of detecting and removing unnecessary conductive balls (extra balls, double balls, etc.) that are sucked and held by a mount head before mounting, or mounting a conductive ball. There has been a method of detecting and removing unnecessary conductive balls (remaining balls and the like) left on a mount head after being mounted on an object.
[0003]
However, strictly speaking, the ball holding surface of the mount head is not a perfect horizontal plane but has a slight inclination. Therefore, when the diameter of the conductive ball is very small with a diameter of 0.1 mm, this inclination is not a mere error, and when controlled with a constant approach amount, each unnecessary conductive ball to be removed and a suction nozzle serving as a removing means thereof Are different from each other, and if they are not brought close enough, the removal effect may not be exhibited.
[0004]
[Problems to be solved by the invention]
The present invention determines the inclination of the ball holding surface of the mount head in advance before the operation of the conductive ball mounting device, for example, when replacing the suction plate provided with the suction hole serving as the ball holding surface, so that unnecessary conductive balls can be obtained. The removal amount of the suction nozzle as the removing means and the descending amount of the mount head differ depending on the position where the removal is performed, the distance between the ball holding surface and the tip of the suction nozzle as the removing means is kept constant, and the unnecessary conductive It is an object of the present invention to provide a conductive ball removing device capable of removing a conductive ball.
[0005]
[Means for Solving the Problems]
The first invention employs the following means in a conductive ball removing device in order to solve the above problems.
First, a mount head having a ball holding surface for attracting and holding a conductive ball, and mounting the held conductive ball on an object to be mounted, and an unnecessary conductive ball approaching the ball holding surface and being on the ball holding surface The conductive ball mounting device includes a removing means for removing the gas by acting on the ball holding surface and an elevating means for relatively bringing the removing means closer to the ball holding surface.
Secondly, there is provided an interval detecting means for detecting that the ball has relatively approached the ball holding surface and has approached a predetermined interval.
Third, based on the relative approaching movement distance between the ball holding surface and the distance detecting means when the predetermined distance is reached, the relative movement of the mount head and the removing means when removing unnecessary conductive balls is performed. Determine the amount.
[0006]
The second invention relates to an improvement of the first invention, wherein the distance detecting means detects a nozzle for injecting or sucking gas while approaching the ball holding surface relatively, and detects a pressure fluctuation in the nozzle. And a pressure detecting means for detecting that the ball holding surface and the nozzle have approached to a predetermined interval by detecting a predetermined pressure.
Furthermore, a third invention relates to an improvement of the first or second invention, wherein the removing means is constituted by a nozzle for jetting or sucking a gas.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described along with examples with reference to the drawings. FIG. 1 is a schematic explanatory view showing the entire solder ball mounting apparatus 1. In the embodiment, a solder ball 2 having a diameter of 0.1 mm is used as a conductive ball in the present invention. Of course, the conductive balls in the present invention are not limited to the above-mentioned solder balls 2. In the embodiment, the wafer 31 is used as an object to be mounted. However, a printed wiring board such as a BGA board may be used.
[0008]
The solder ball mounting device 1 includes, from the left side in FIG. 1, a ball supply device 3 in which a large number of solder balls 2 are stored, a mount head 4 for holding the solder balls 2 by vacuum suction, and an X of the mount head 4. Inspection for detecting the position of the axis moving device 6 (the device for moving left and right in FIG. 1), the Z-axis moving device 7 for the mount head 4 (the device for moving vertically in FIG. 1), and the unnecessary solder balls 22 and 23. A camera 8, a ball removing device 9 that directly acts on the unnecessary solder balls 22, 23, and a pressure detecting device that detects that the ball holding surface 11 and the ball removing device 9 have approached to a predetermined distance (shown in FIG. 1). 2, and a Y-Θ table 32 on which a wafer 31 that moves in the Y-Θ axis direction is placed.
[0009]
An X-axis moving device 6 of the mount head 4 (a moving device in the left and right direction in FIG. 1) and a Z-axis moving device 7 of the mount head 4 (a moving device in the vertical direction in FIG. 1) The moving mechanism moves the mount head 4 relatively to the Y-Θ table 32. Of course, it is only necessary to be relatively movable, so that the Y- 移動 table 32 or the like may move or both may move.
[0010]
The movement of the mount head 4 by the X-axis moving device 6 and the Z-axis moving device 7 includes a movement above the ball supply device 3, a vertical movement for sucking the ball, a movement above the Y-table 32, and a ball mounting operation. There is up and down movement for. The Z-axis moving device 7 includes a servomotor (not shown), a ball screw that is rotated by the servomotor, and a nut portion that changes the rotation of the ball screw up and down. In addition to the above functions, it also serves as a drive mechanism for moving the mount head 4 up and down for detecting pressure fluctuations in the suction nozzle 10.
[0011]
The Y-Θ table 32 has a Θ-axis drive unit installed on a Y-axis drive table, and is configured to be movable in a plane in the Y-axis direction (the front-rear direction in FIG. 1) and the Θ-axis direction (rotation direction). , Is used for positioning at the time of mounting.
[0012]
The mount head 4 has a ball holding surface 11 formed with a plurality of suction holes 15 for sucking and holding the solder balls 2 as shown in FIG. The mount head 4 is connected to a vacuum source (not shown), and sucks and holds the solder balls 2 in a large number of suction holes 15 formed in the ball holding surface 11 by negative pressure from the vacuum source.
[0013]
The inspection camera 8 detects the position of the unnecessary solder ball 22. More precisely, the inspection camera 8 extraly holds the solder ball 2 by suction on the mount head 4 held by the ball supply device 3 as shown in FIG. 3B, the solder balls 2 are not mounted on the mount head 4 after the solder balls 2 are mounted on the wafer 31 at the positions of the unnecessary solder balls 22 on the ball holding surface 11 or on the mounting portion as shown in FIG. The position of the solder ball 23 on the ball holding surface 11 is detected.
[0014]
That is, the detection of the unnecessary solder balls 22 and 23 by the inspection camera 8 is performed on both the forward path (the moving path before the ball is mounted) and the return path (the moving path after the ball mounting) of the mount head 4. FIG. 3A is an inspection image detected by the inspection camera 8 on the outward path, in which the solder balls 2 properly sucked and held and the unnecessary solder balls 22 as surplus balls are detected on the ball holding surface 11. ing. On the other hand, FIG. 3B is an inspection image detected by the inspection camera 8 on the return path, and the remaining balls that are not mounted are detected on the ball holding surface 11 as unnecessary solder balls 23. Note that reference numeral 15 in the drawing denotes a suction hole.
[0015]
The ball removing device 9 has a suction nozzle 10 as shown in FIG. 2, and the suction nozzle 10 is connected to a vacuum source (not shown) via a suction passage 16. In the case where the diameter of the solder ball 2 is 0.1 mm, the suction opening diameter of the suction nozzle 10 is 0.8 mm, and the suction nozzle 10 is brought as close as possible to the ball holding surface 11 so as not to interfere with the solder ball 2 which is normally sucked and held. Thus, it is formed so as to surround the unnecessary solder ball 22 so that the outside air flowing from almost the entire circumference of the unnecessary solder ball 22 acts.
[0016]
The operation of removing the unnecessary solder balls 22 and 23 by the suction nozzle 10 is performed as follows. Unnecessary solder balls 22 such as extra balls and double balls on the outward path are suction-removed, and unnecessary solder balls such as remaining balls on the return path are suction nozzles 10 to the extent that they do not contact the ball holding surface 11. , The unnecessary solder ball 23 is positioned in the opening at the tip end of the suction nozzle 10, is surrounded by the opening edge, and is removed by bringing the mount head 4 or the suction nozzle 10 into lateral contact with the opening edge.
[0017]
The suction nozzle 10 is equipped with an air cylinder 12 and a Y-axis moving mechanism 13 for moving in the front-rear direction in FIG. 1 as elevating means for approaching a predetermined position on the lower surface of the mount head 4. Of course, the approach and isolation between the suction nozzle 10 and the lower surface of the mount head 4 may be relative, and therefore any one of the air cylinder 12 and the Z-axis moving device 7 for the mount head 4 may be used.
[0018]
A pressure detecting device 5 for detecting a change in the internal pressure of the suction nozzle 10 is connected in the middle of the suction passage 16 to the suction nozzle 10. That is, the suction nozzle 10 has a role as a nozzle as a removing means in the present invention, and at the same time, a role as a nozzle constituting the interval detecting means. The pressure detecting device 5 in the embodiment detects a change in the internal pressure in the suction nozzle 10, that is, a change in the suction pressure. Therefore, the vacuum source connected to the suction nozzle 10 becomes a negative pressure source for suction used for removing the unnecessary solder balls 22 and 23 and a negative pressure source for generating internal pressure in the suction nozzle 10 for pressure detection. The internal pressure in the suction nozzle 10 detected by the pressure detection device 5 is input to a control unit 17 provided inside the base 14 and stored.
[0019]
Next, a method of detecting the amount of movement of the mount head 4 and the suction nozzle 10 up to the ball removal position in this embodiment will be described. First, before the mounting operation of the solder ball mounting device 1, the air cylinder 12 of the suction nozzle 10 existing at the origin position as shown in FIG. 4 (A) is operated, and the suction nozzle 10 sucks and holds the solder ball 2. From below the predetermined detection position of the ball holding surface 11 of the mount head 4 that has not been moved, the mount head 4 is raised to a predetermined position shown in FIG. Here, three or more positions on the same plane as the ball holding surface 11 provided with the suction holes 15 and no suction holes 15 are defined as the predetermined detection positions.
[0020]
On the other hand, the mount head 4 is also lowered by a predetermined amount from the origin position shown in FIG. 4 (A) by the Z-axis moving device 7, and reaches the position shown in FIG. 4 (B). Thereafter, as shown in FIG. 4C, the ball is gradually approached to the ball holding surface 11 at a low speed. When the gap between them becomes small, the pressure in the suction nozzle 10 fluctuates. From the position shown in FIG. 4 (C), the pressure fluctuation in the suction nozzle 10 is detected by the pressure detecting device 5, and when the pressure becomes a predetermined pressure, the distance between the tip of the suction nozzle 10 and the lower surface of the mount head 4 is reduced. At a predetermined interval. FIG. 4D shows this position. At this time, the control unit 17 obtains the amount of lowering of the mount head 4 from the origin position, that is, the amount of approach movement, when the distance from the tip of the suction nozzle 10 becomes a predetermined distance. In the case where a mechanism that can be gradually raised and stopped at an arbitrary position is provided by using a servomotor or the like as the lifting / lowering means of the suction nozzle 10, the mount head 4 is stopped and the suction nozzle 10 is moved to the lower surface. Alternatively, the pressure may be gradually approached to detect a predetermined pressure, and the approach movement amount of the suction nozzle 10 from the origin position to a predetermined interval may be obtained. Further, the predetermined pressure may be detected by gradually lowering the mount head 4 and gradually raising the suction nozzle 10 so as to be relatively close to each other by a combined raising and lowering movement of both.
[0021]
The control unit 17 further obtains and stores the inclination of the lower surface of the mount head 4 by a plane equation from the approach movement amounts for the three points thus obtained. That is, the plane position (X, Y) and height (Z) of each point are determined by the amount of lowering of the mount head 4 from the mechanical origin position at each point, the amount of upward movement of the suction nozzle 10, or the relative amount of raising and lowering of both. Is obtained, and the inclination of the lower surface of the mount head 4 with respect to the ideal horizontal plane is derived and stored by the plane equation (AX + BY + CZ). By calculating the inclination of the lower surface of the mount head 4, it is possible to determine, for each position of the ball holding surface 11, the relative amount of elevation between the mount head 4 and the suction nozzle 10 that causes the suction nozzle 10 to approach a predetermined distance. The distance between the ball holding surface 11 and the suction nozzle 10 at the time of removing a solder ball can be set to a constant distance required for removal at any position on the ball holding surface 11.
[0022]
In the embodiment, when the inclination of the lower surface of the mount head 4 is detected by the suction nozzle 10, the suction pressure is used by using the negative pressure by suction. In the case of the conductive ball removing device for removing, the nozzle may be approached while blowing air from the nozzle 10 to detect a positive pressure fluctuation.
[0023]
After the detection of the inclination of the lower surface of the mount head 4 and the end of the storage operation, the mount head 4 moves above the ball supply device 3 by the operation of the X-axis moving device 6. Next, the mount head 4 is lowered by the operation of the Z-axis moving device 7, and the solder balls 2 are sucked from the ball supply device 3 into the suction holes 15 provided in the ball holding surface 11 of the mount head 4. Is lifted by the Z-axis moving device 7 again.
[0024]
The mount head 4 that has attracted the solder ball 2 continues to move further rightward in FIG. 1 by the X-axis moving device 6 and reaches above the inspection camera 8. Here, the inspection camera 8 performs photographing, and carries out image processing based on the photographed data. The ball holding of the unnecessary solder balls 22 additionally held by the mount head 4 holding the solder balls 2 by suction by the ball supply device 3 is performed. The position on the surface 11 is recognized and detected.
[0025]
First, the mount head 4 and the suction nozzle 10 are relatively moved in the X and Y directions, and the suction nozzle 10 is positioned below the unnecessary solder ball 22 to be removed. Next, the air cylinder 12 of the suction nozzle 10 located at the origin position is operated to raise the suction nozzle 10 from a position below the detection position of the unnecessary solder ball 22 to a predetermined position.
[0026]
On the other hand, the mount head 4 also descends from the origin position of the mount head 4 in accordance with the tilt data of the lower surface of the mount head 4 previously detected and stored from the position data of the unnecessary solder balls 22 obtained by the image processing. First, the ball holding surface 11 is gradually lowered from the origin position by a predetermined amount by the Z-axis moving device 7, and then the ball holding surface 11 is gradually approached to the suction nozzle 10 at a low speed, and is then approached to an interval necessary for removal. The unnecessary solder balls 22 are removed by suction using the suction nozzle 10.
[0027]
After removing the unnecessary solder balls 22, the mount head 4 further moves rightward in FIG. 1 and moves above the ball mounting position of the Y-Θ table 32. Next, the mount head 4 is moved down onto the wafer 31 by the Z-axis moving device 7, the suction is released, and the ball mounting operation is performed.
[0028]
After the ball mounting operation, the mount head 4 enters a return path toward the ball supply device 3. When the mount head 4 reaches the upper side of the inspection camera 8 during the return path, it is recognized by the inspection camera 8 and the solder balls 23 remaining on the mount head 4 are removed. The position on the ball holding surface 11 is detected. Based on the detection result, the mount head 4 and the suction nozzle 10 are relatively moved in the X and Y directions, and the suction nozzle 10 is positioned below the unnecessary solder ball 23 to be removed.
Next, the air cylinder 12 of the suction nozzle 10 located at the origin position is operated, and the suction nozzle 10 is raised from below the detection position of the unnecessary solder ball 22 to a predetermined position.
[0029]
On the other hand, the mount head 4 also descends from the origin position of the mount head 4 in accordance with the tilt data of the lower surface of the mount head 4 previously detected and stored from the position data of the unnecessary solder balls 23 obtained by the image processing. First, the ball holding surface 11 is gradually lowered from the origin position by a predetermined amount by the Z-axis moving device 7, and then gradually approaches the suction nozzle 10 at a low speed to approach the remaining unnecessary solder balls 23. 23 is positioned in the distal end opening of the suction nozzle 10 and is surrounded by the opening edge, and the mount head 4 is moved laterally so as to abut on the opening edge to be removed.
[0030]
In the case where the unnecessary solder balls 23 as take-out balls are used, the mount head 4 is lowered more than the unnecessary solder balls 22 as surplus balls, and the approach becomes closer. Of course, the amount of the lowering also depends on the diameters of the solder balls 2, 22, and 23.
[0031]
Thereafter, the mount head 4 returns to the ball supply device 3, and a series of operations of the solder ball mounting device 1 is completed. During the series of operations, the detection of the unnecessary solder balls 22 and 23 and the removal of the balls by the inspection camera 8 are performed twice in the forward and backward directions in the embodiment. However, either one may be selected according to the purpose.
[0032]
In the embodiment, the approach between the lower surface of the mount head 4 and the suction nozzle 10 to the predetermined interval required for removing the unnecessary solder balls 22 and 23 from the predetermined position is performed by lowering the mount head 4, but is performed by raising the suction nozzle 10. Of course, it is also possible to carry out by raising and lowering both. Further, the interval detecting means can be configured by providing a detecting unit such as a capacitance sensor, a laser displacement sensor, or a contact sensor at the tip of a nozzle constituting the removing means, in addition to the embodiment.
[0033]
【The invention's effect】
The present invention includes an interval detecting means for detecting that the ball holding surface is relatively close to the ball holding surface and reaches a predetermined interval, and the relative approach between the ball holding surface and the interval detecting means when the predetermined interval is reached. Based on the amount of movement, the relative amount of lifting and lowering of the mount head and the removing means when removing unnecessary conductive balls is determined, so the amount of movement required for removing unnecessary conductive balls is determined at the point of unnecessary conductive balls. The conductive ball removing device can be obtained every time, and the removing means can be moved by a moving amount adapted to a removed portion.
[0034]
According to the second aspect of the present invention, the nozzle includes a nozzle that injects or sucks gas while relatively approaching the ball holding surface, and a pressure detecting unit that detects a pressure change in the nozzle. Interval detection means is provided for detecting that the ball holding surface and the nozzle have approached to a predetermined interval by detecting, and based on the relative approach movement amount of the ball holding surface and the nozzle when the predetermined interval is reached, unnecessary Since the relative lifting amount of the mount head and the removing means when removing the conductive balls is determined, the amount of movement required for removing the unnecessary conductive balls can be determined without using expensive equipment. The conductive ball removing device can be obtained every time, and the removing means can be moved by a moving amount adapted to a removed portion.
[0035]
According to the third aspect of the present invention, since the removing means is constituted by a nozzle for injecting or sucking a gas, the nozzle of the removing means and the nozzle of the interval detecting means can be shared, or the removing means can be used. A gas or a moving device can be used for the interval detecting means, and it has become possible to prevent the device from becoming complicated.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view showing the entire solder ball mounting apparatus according to the present embodiment. FIG. 2 is a front explanatory view showing a ball removing apparatus. FIG. 3 is a plan explanatory view showing an inspection image by a detection camera. (A) is a diagram showing an inspection image before mounting a ball, and (B) is a diagram showing an inspection image after mounting.
4A and 4B are diagrams illustrating a change in a positional relationship between a mount head and a nozzle, wherein FIG. 4A is an explanatory diagram illustrating an origin position of both, and FIG. FIG. 7 is an explanatory view showing a state in which only the mount head descends at a low speed, and FIG. 7D is an explanatory view showing a predetermined pressure detection position.
[Explanation of symbols]
1. . . . . . 1. Solder ball mounting device . . . . . 2. solder balls . . . . . 3. Ball supply device . . . . . Mount head5. . . . . . Pressure detector 6. . . . . . X-axis moving device7. . . . . . 7. Z-axis moving device . . . . . . Inspection camera 9. . . . . . Ball removing device 10. . . . . Suction nozzle 11. . . . . Ball holding surface 12. . . . . Air cylinder 13. . . . . 13. Y-axis moving mechanism . . . . Base 15. . . . . Adsorption hole 16. . . . . Suction passage 17. . . . . Control units 22, 23. . Unnecessary solder balls 31. . . . . . Wafer 32. . . . . . Y-table

Claims (3)

It has a ball holding surface for attracting and holding the conductive balls, and a mount head that mounts the held conductive balls on the object to be mounted and an unnecessary conductive ball on the ball holding surface that approaches the ball holding surface. In a conductive ball mounting apparatus having a removing means for removing and an elevating means for relatively bringing the removing means closer to the ball holding surface, it is detected that the conductive ball is relatively close to the ball holding surface and has reached a predetermined distance. The distance between the mount head and the removing means for removing unnecessary conductive balls based on the relative approach movement amount between the ball holding surface and the distance detecting means when the predetermined distance is reached. A conductive ball removing device for determining an amount of vertical movement. The interval detecting means comprises a nozzle for injecting or sucking a gas while approaching the ball holding surface relatively, and a pressure detecting means for detecting a pressure change in the nozzle, and detects a predetermined pressure to hold the ball. 2. The conductive ball removing device according to claim 1, wherein it is detected that the surface and the nozzle have approached to a predetermined interval. 3. The conductive ball removing device according to claim 1, wherein said removing means comprises a nozzle for injecting or sucking a gas.

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