JP4487142B2 - Solder ball mounting method and apparatus - Google Patents

Description

  The present invention relates to an improvement of a solder ball mounting method and an apparatus therefor, and more specifically, a solder ball adsorbed on a lower end surface of a suction head whose inside is evacuated by a vacuum means is mounted at a predetermined position on a substrate. The present invention relates to a solder ball mounting method and an improvement of the apparatus.

  A solder ball mounting method and apparatus for mounting a solder ball attracted to a lower end surface of a suction head whose inside is evacuated by a vacuum means at a predetermined position on a substrate, and a device therefor exist as disclosed in Patent Document 1 did.

  However, in the conventional method and apparatus disclosed in Patent Document 1, after the solder ball has landed on the substrate or the pad, the solder ball is stopped on the substrate or the pad, and the vacuum suction is stopped there. Therefore, if there is a gap between the solder ball and the suction port of the suction head when landing, air leakage occurs, and the flux is sucked from the gap between the solder ball and the suction head of the suction head and adheres to the vicinity of the gap. There was a thing. This is accompanied by a problem that when the suction head is lifted after mounting the solder ball, the solder ball is not separated from the suction head.

Japanese Patent No. 3228140

  The present invention releases the vacuum of the suction head immediately before the solder ball lands on the substrate to prevent the flux from adhering to the suction part such as the suction port of the suction head, and the solder ball does not leave the suction head. It is an object of the present invention to provide a solder ball mounting method and apparatus for preventing the above.

In order to solve the above-mentioned problem, the first invention adsorbs a solder ball adsorbed to a suction port which is provided on a lower end surface of an adsorption head whose inside is evacuated by a vacuum means and has a tapered surface formed on the lower end side. In the solder ball mounting method in which the head is lifted and mounted at a predetermined position on the substrate, when the solder ball is placed on the substrate, the solder ball is positioned above the position where the solder ball lands on the substrate and below the substrate and the suction head. after the distance between the end face the vacuum was released in the adsorption head in diameter following positions of the solder balls, a solder ball mounting method characterized by lowering the suction head to the lowered end below the relevant position.

According to a second aspect of the present invention, there is provided a suction head having a suction port formed with a tapered surface for sucking a solder ball on the lower end side, a vacuum means for applying a vacuum in the suction head, and an elevating means for raising and lowering the suction head. In a solder ball mounting apparatus for mounting a solder ball adsorbed by the suction head at a predetermined position on the substrate by raising and lowering the suction head by the lifting means, the solder ball is placed on the substrate when the solder ball is placed on the substrate. After releasing the vacuum from the vacuum means applied in the suction head at a position above the landing position where the distance between the substrate and the lower end surface of the suction head is less than the diameter of the solder ball , the suction head is applied. a solder ball mounting apparatus characterized by being configured so as to descend from said phase location to the lowered end of the lower.

In the first invention, when the suction head that has attracted the solder ball descends to the lower end and places the solder ball on the substrate, the solder ball is positioned above the position where the solder ball lands on the substrate. Since the solder ball mounting method releases the vacuum inside the suction head at a position where the distance to the lower end surface is less than the diameter of the solder ball, the flux may be sucked into the suction head suction port. At a certain position, since the vacuum has already been released, there is no possibility of the flux being sucked and adhering to the suction portion such as the suction port of the suction head.

Those in the first invention, position you cancel the vacuum, the solder ball is an above the position where the land on the substrate, the distance between the lower end surface of the substrate and the suction head has a diameter following positions of the solder balls Therefore, even if the solder ball that has been attracted to the suction head by releasing the vacuum is detached from the suction head, the upper end of the solder ball is located above the lower end of the suction surface of the suction port. It stopped inside and the solder ball would not roll.

In the second invention, a suction head having a suction port formed with a taper surface for sucking a solder ball on the lower end side, a vacuum means for applying a vacuum in the suction head, a lifting means for raising and lowering the suction head, In a solder ball mounting apparatus for mounting a solder ball adsorbed by the suction head at a predetermined position on the substrate by raising and lowering the suction head by the lifting means, the solder ball is placed on the substrate when the solder ball is placed on the substrate. After releasing the vacuum from the vacuum means applied in the suction head at a position above the landing position where the distance between the substrate and the lower end surface of the suction head is less than the diameter of the solder ball , the suction head is applied. since from said phase location to the lowered end of the lower those configured to descend, in a position where there is a possibility that flux is sucked to the suction port of the suction head, is already vacuum Possibility of flux because it is divided is attracted to adhere to the suction unit, such as the suction port of the suction head becomes no solder ball mounting device.

Although it is an effect of the embodiment, since the positive pressure is applied to the suction head after the vacuum in the suction head is released, even if the solder ball does not detach from the suction port of the suction head by releasing the vacuum. However, the solder ball can be forcibly detached by positive pressure. As a result, when the suction head is raised after placing the solder ball on the substrate, the solder ball can be reliably detached from the suction head.

Similarly, although it is an effect of the embodiment, since a means for raising the suction head after waiting for a predetermined time at the lowering end is added, the effect of releasing the vacuum can be surely exhibited. .

  Hereinafter, embodiments of the present invention will be described together with examples according to the drawings. FIG. 1 is a schematic explanatory view showing the entire solder ball mounting apparatus 1. The solder ball mounting apparatus 1 includes, from the left side in FIG. A suction head 4 having a suction port 41 for sucking and holding the ball 2 by vacuum suction, an X-axis moving device 6 (moving device to the left and right in FIG. 1) serving as a lateral movement device of the suction head 4, and the suction head 4 again A Z-axis moving device 7 (moving device in the vertical direction in FIG. 1) and a table 22 on which the substrate 21 is positioned and placed at a predetermined position are provided.

  Note that the solder ball mounting apparatus assumes that the table 22 on which the substrate 21 is placed can be moved in the XY axis direction and the Θ axis direction, and the position of the substrate 21 is observed with an upper camera and automatically aligned. Another configuration may be used.

  The movement of the suction head 4 in the X-axis moving device 6 and the Z-axis moving device 7 is for upward movement of the ball supply device 3, upward and downward movement for ball adsorption, upward movement of the table 22, and ball mounting operation. There is up and down movement.

  FIG. 2 is an enlarged side view illustrating the relationship between the suction head 4 and the Z-axis moving device 7. The Z-axis moving device 7 includes a Z-axis drive motor 5, a feed screw 8 that is rotated by the Z-axis drive motor 5, and a nut member 9 that is raised and lowered by the rotation of the feed screw 8.

  A base 10 is integrally attached to the nut member 9 and constitutes an operating portion of the Z-axis moving device 7 serving as a lifting mechanism. The suction head 4 is suspended from the base 10 via a fixture 11.

  The suction head 4 sucks and holds the solder ball 2 by the suction port 41 and mounts the solder ball 2 on the substrate 21. A number of suction ports 41 for directly sucking the solder ball 2 are arranged at predetermined positions on the lower surface. Open. A tapered surface 41a is formed on the lower end side of each suction port, and the adsorbed solder balls 2 come into contact with the tapered surface 41a. The suction head 4 is connected to a vacuum means 12 that applies a vacuum to the internal space 43 of the suction head 4 and a pressurizing means 13 that applies a positive pressure to the internal space 43 of the suction head 4.

  The vacuum means 12 includes a vacuum source 14 (for example, a blower or a vacuum pump) and an electromagnetic opening / closing valve 15 provided between the vacuum source 14 and the internal space 43, and the inside of the suction head 4 is opened and closed by opening and closing the electromagnetic opening / closing valve 15. A vacuum is applied to or released from the space 43. Further, the vacuum means 12 is provided with an electromagnetic on-off valve 16 and a throttle valve 17 which are branched from between the vacuum source 14 and the electromagnetic on-off valve 15, and by opening the electromagnetic on-off valve 16 during vacuum suction, The vacuum pressure acting on the internal space 43 can be reduced, and the vacuum pressure can be adjusted by the throttle valve 17.

  The pressurizing means 13 includes a compressed gas source 18 (for example, a compressor) and an electromagnetic on-off valve 19 provided between the compressed gas source 18 and the internal space 43, and positive pressure is applied to the internal space 43 by opening and closing the electromagnetic on-off valve 19. Is granted or released. Then, by opening the electromagnetic opening / closing valve 15, the inside of the suction head 4 is vacuum sucked by the vacuum source 14 to suck and hold the solder ball 2 at the suction port 41, the electromagnetic switching valve 15 is closed, and the electromagnetic switching valve 19 is opened. By opening, a positive pressure is applied by supplying a compressed gas from the compressed gas source 18 to the inside of the suction head 4, and the solder ball 2 is reliably released from the suction port 41.

  Reference numeral 20 in FIG. 2 denotes a control device, which is provided with a timer (not shown), and gives operation commands to the Z-axis drive motor 5 and the electromagnetic on-off valves 15, 16, 19 at predetermined timings. .

  In the following, the operation of the embodiment will be described with reference to the flowchart of FIG. First, as a first step, the substrate 21 transported by a substrate transport device (not shown) is held at a predetermined position on the table 22.

  As a second step, the flux 23 is applied to a predetermined position of the substrate 21 by a flux application device (not shown). In parallel with the second step, as the third step, the X-axis moving device 6 operates, the suction head 4 moves above the ball supply device 3 that is a ball pool and stops, and the Z-axis moving device 7 operates. To descend into the ball supply device 3. At this time, the electromagnetic on / off valve 15 is opened with the electromagnetic on / off valve 16 closed, a vacuum is applied to the internal space 43 of the suction head 4 by the vacuum source 14, and the solder ball 2 is placed in the suction port 41 of the suction head 4. Hold by adsorption.

  As a fourth step, if all the suction ports 41 of the suction head 4 suck the solder balls 2, a strong suction force is no longer necessary, so the electromagnetic on-off valve 16 is opened and the vacuum pressure in the internal space 43 of the suction head 4 is opened. Reduce.

  As a fifth step, the suction head 4 is raised by the Z-axis moving device 7 and moved by the X-axis moving device 6 to above the solder ball mounting position of the substrate 21 placed on the table 22.

  As a sixth step, the suction head 4 starts to descend toward the descending end by the Z-axis moving device 7. Here, the descending end is a position set so that the lowest position of the solder ball 2 indicated by a two-dot chain line in FIG. 4 is in contact with the electrode 24 of the substrate 21, such as a manufacturing error in the ball diameter of the solder ball 2. May be slightly away from the substrate 21. At this time, the distance between the lower end face 42 of the suction head 4 and the substrate 21 is L1.

  Subsequently, as a seventh step, the position immediately before the solder ball 2 attracted to the suction head 4 lands on the substrate 21 (the position where the distance between the lower end surface 42 of the suction head 4 and the substrate 21 in FIG. 4 is L2). ), The electromagnetic on-off valve 15 is closed, the vacuum application from the vacuum source 14 is stopped, and the vacuum in the suction head 4 is released. The position immediately before releasing the vacuum is a position where the distance L2 between the substrate 21 and the lower end surface 42 of the suction head 4 is equal to or less than the diameter d of the solder ball. Even when the solder ball 2 is removed from the suction head 4 when the vacuum is released in the seventh step, the distance L2 between the lower end surface 42 of the suction head 4 and the substrate 21 is smaller than the diameter d of the solder ball 2. The solder ball 2 does not roll anywhere.

  As the eighth step, the lowering of the suction head 4 continues, and the attracted solder ball 2 lands on the substrate 21, and at the same time, the electromagnetic on-off valve 19 opens, and the compressed gas source 18 enters the inner space 43 of the suction head 4. Positive pressure is applied. In this eighth step, the suction head 4 continues to descend to a position where the solder ball 2 and the substrate 21 are in contact with each other, so that the solder ball 2 is displaced from the correct position when the solder ball 2 is dropped from the suction head 4 in the seventh step. Even so, the solder ball 2 is positioned at a predetermined correct position by the tapered surface 41 a of the suction port 41.

  As a ninth step, the suction head 4 stands by at the descending end until the internal space 43 of the suction head 4 returns to atmospheric pressure. Subsequently, as the tenth step, when the internal space 43 of the suction head 4 returns to atmospheric pressure, the suction head 4 is raised by the Z-axis moving device 7 and one cycle is completed. Here, the flux 23 does not adhere to the suction head 4, and unnecessary solder balls such as double balls do not adhere at the next suction of the solder balls. The solder ball mounting apparatus 1 in the present embodiment repeats the cycle consisting of the above steps, and the solder ball 2 is mounted.

  In the present embodiment, the solder ball mounting apparatus 1 on which a plurality of solder balls 2 are mounted is assumed. However, the present invention is naturally applicable to a single solder ball mounting apparatus.

Schematic explanatory diagram showing the entire solder ball mounting apparatus according to the present embodiment Partially enlarged side view showing the relationship between the suction head and the Z-axis moving device Flow diagram showing solder ball mounting operation Enlarged explanatory diagram showing the previous position

Explanation of symbols

1. . . . . . Solder ball mounting device . . . . . 2. Solder balls . . . . . 3. Ball supply device . . . . . 4. Suction head . . . . . Z-axis drive motor . . . . . X-axis moving device 7. . . . . . Z-axis moving device 8. . . . . . Lead screw 9. . . . . . Nut member 10. . . . . Base 11. . . . . Attachment 12. . . . . Vacuum means 14. . . . . Vacuum source 15, 16, 19. . . . . Electromagnetic on-off valve 17. . . . . Throttle valve 18. . . . . Compressed gas source 20. . . . Controller 21. . . . . . Substrate 22. . . . . . Table 23. . . . . . Flux 41. . . . . Suction port 41a. . . . Tapered surface 42. . . . . Lower end surface 43. . . . . Interior space

Claims (2)

Mounted at a predetermined position on the substrate by moving the suction head up and down the solder ball, which is provided on the lower end surface of the suction head whose inside is evacuated by vacuum means, and the suction port has a tapered surface on the lower end side In the solder ball mounting method, when placing the solder ball on the substrate, the solder ball is positioned above the position where the solder ball lands on the substrate, and the distance between the substrate and the lower end surface of the suction head is equal to or smaller than the diameter of the solder ball. after releasing the vacuum in the suction head Te, solder ball mounting method characterized by lowering the suction head to the lowered end of the lower than the position. A suction head having a suction port formed with a tapered surface for sucking a solder ball on the lower end side, a vacuum means for applying a vacuum in the suction head, and a lifting means for raising and lowering the suction head. In a solder ball mounting apparatus that mounts a solder ball adsorbed by the suction head at a predetermined position on the substrate by raising and lowering the suction head, when the solder ball is placed on the substrate, the solder ball is positioned above the position where the solder ball lands on the substrate. there are, after releasing the vacuum from the vacuum means for the distance between the substrate and the lower end surface of the suction head is applied to the suction head at the diameter following positions of the solder balls, a suction head from below those said phase location A solder ball mounting device configured to descend to a descending end.

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