JP2013162090A - Electronic component mounting apparatus and electronic component mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component mounting apparatus which comprises mounting heads using shaft type linear motors to reduce a nozzle pitch and allows a large stroke of nozzles without causing increase of the mounting head size or decrease of the mounting precision.SOLUTION: A main frame 10 is provided with a sub-frame 20 that can be vertically moved by a servomotor 30. The sub-frame 20 is provided with a plurality of nozzle units 40 that can be vertically moved by shaft type linear motors 50. A nozzle 41 is placed at an end of each of the nozzle units. The nozzles 41 are vertically moved by a combination of vertical movement of the sub-frame 20 by the servomotor 30 and vertical movement of the nozzle units 40 by the shaft type linear motors 50.

Description

  The present invention relates to an electronic component mounting apparatus and an electronic component mounting method for mounting an electronic component such as an IC chip on a printed board. In this specification, an electronic component mounting apparatus is simply referred to as a mounting apparatus, an electronic component is simply referred to as a component, and a printed circuit board is simply referred to as a board.

  As electronic devices become smaller and lighter and have higher functionality, there is a need for further miniaturization and higher integration of substrates mounted thereon. In such a miniaturized and highly integrated substrate, the mounting locations on which electronic components are mounted are narrowed, and therefore the nozzle pitch is also required to be reduced in the mounting head.

  In response to such a narrow pitch requirement, Patent Document 1 proposes a mounting apparatus including a mounting head using a shaft type linear motor. Specifically, in the mounting head of Patent Document 1, a shaft type linear motor is arranged vertically above each of a plurality of nozzle units having nozzles attached to the lower end, and each nozzle unit is individually moved up and down by the shaft type linear motor. I try to let them.

  However, in the mounting apparatus disclosed in Patent Document 1, if the vertical stroke of the nozzle is to be increased, it is necessary to lengthen the shaft of the shaft type linear motor. As a result, the shaft type linear motor increases in size up and down, and the mounting head As the height of the mounting head increases, the position of the center of gravity of the mounting head also increases. If the position of the center of gravity of the mounting head is increased, vibration is likely to occur in the mounting head, and the nozzle is also vibrated accordingly, which causes a problem that mounting accuracy is lowered.

  In addition, when the nozzle stroke is increased, the spline shaft of the ball spline in the nozzle unit extends greatly downward from the held part, making it easier for the nozzle at the tip of the spline shaft to vibrate. There arises a problem that accuracy is lowered.

  Thus, when trying to increase the stroke of the nozzle in the mounting apparatus of Patent Document 1, there is a problem that the mounting head is increased in size in the vertical direction and mounting accuracy is lowered. For this reason, in the mounting apparatus of patent document 1, it is difficult to lengthen the stroke of a nozzle. If the nozzle stroke is short, the height of components that can be mounted is restricted, and the specifications of the components to be mounted are limited.

International Publication No. 2007/111296

  The problem to be solved by the present invention is that in an electronic component mounting apparatus equipped with a mounting head using a shaft type linear motor to narrow the nozzle pitch, the mounting head is increased in size and mounting accuracy is reduced. There is no need to increase the stroke of the nozzle.

  The electronic component mounting apparatus according to the present invention is an electronic component mounting apparatus including a mounting head that sucks and holds a plurality of electronic components by a plurality of nozzles and mounts each electronic component at a plurality of mounting locations on a printed circuit board. A mounting head includes a main frame, a sub-frame that can be moved up and down with respect to the main frame, a servo motor that is provided in the main frame and moves the sub-frame up and down, and the nozzle is attached to the lower end of the servo motor. A plurality of nozzle units provided so as to be movable up and down with respect to the sub-frame, and fixed to the sub-frame vertically above each nozzle unit, and each nozzle unit individually with respect to the sub-frame. A plurality of shaft-type linear motors that are moved up and down, and provided on the subframe. It is characterized in further comprising a rotary device for rotating the respective nozzle units.

  The electronic component mounting method of the present invention is the electronic component mounting method of the electronic component mounting apparatus of the present invention, wherein the sub-frame is moved up and down by the servo motor, and the nozzle units of the respective shaft type linear motors. Each of the nozzles is moved up and down by a combination with vertical movement.

  According to the present invention, the nozzle unit is moved up and down by the shaft type linear motor fixed to the sub frame, and the sub frame is moved up and down by the servo motor, so that the stroke of the shaft type linear motor is not increased. The nozzle stroke can be increased by moving the subframe up and down. Therefore, the stroke of the nozzle can be increased without incurring the problems of the increase in the size of the mounting head and the decrease in mounting accuracy that occur when the stroke of the shaft type linear motor is increased.

  Further, since the nozzle stroke can be increased without causing a decrease in mounting accuracy, there is no restriction on the height of components that can be mounted, and the specifications of components to be mounted can be expanded from small components to large components.

1 is an overall configuration diagram of an electronic component mounting apparatus according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which simplifies and shows the mounting head of embodiment of this invention, (a) is a side block diagram, (b) is a front block diagram which shows a nozzle unit part. It is a front view which shows the nozzle unit and the shaft-type linear motor arrange | positioned perpendicularly upward. (A) shows a state where the nozzle is positioned at the upper limit starting position in the mounting head of the embodiment of the present invention, (b) shows a state where the nozzle is moved downward in the embodiment, and (c) shows In the mounting head of Patent Document 1, the nozzle is moved downward with the same stroke as (b). (A) shows the vertical position of the nozzle in each step, (b) shows the stroke of the servo motor in each step, and (c) shows the stroke of the shaft type linear motor in each step.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, the overall configuration of the electronic component mounting apparatus according to the embodiment of the present invention will be described. FIG. 1 is an overall configuration diagram of an electronic component mounting apparatus according to the present embodiment.

  In FIG. 1, a substrate transfer device 3 for transferring a substrate 2 is arranged extending in the X direction on a base 1 serving as a base of an electronic component mounting apparatus. The substrate transfer device 3 has a function of clamping and holding the substrate 2 and functions as a substrate holding device that holds the substrate 2 transferred in the X direction at a predetermined position. In the present embodiment, the transport direction of the substrate 2 is the X direction, the direction orthogonal to the horizontal plane in the horizontal plane is the Y direction, and the vertical direction orthogonal to the X direction and the Y direction is the Z direction.

A plurality of parts feeders 4 which are examples of feeders for supplying electronic components are arranged on both sides in the Y direction of the substrate transport apparatus 3. The parts feeder 4 functions as an electronic component supply device and sequentially supplies a plurality of electronic components accommodated therein.

A pair of Y tables 5 are arranged at both ends in the X direction of the base 1, and a pair of X tables 6 are bridged over the pair of Y tables 5. A mounting head 100 is mounted on each X table 6. The Y table 5 and the X table 6 are respectively provided with a Y-axis drive mechanism and an X-axis drive mechanism (not shown), and move the mounting head 100 horizontally relative to the base 1.

  2A and 2B are configuration diagrams showing the mounting head of the present embodiment in a simplified manner. FIG. 2A is a side configuration diagram, and FIG. 2B is a front configuration diagram showing a nozzle unit portion.

  The mounting head 100 functions as a mounting head of the mounting apparatus by mounting the main frame 10 on the X table 6 of FIG. A subframe 20 is provided on the main frame 10 so as to be movable up and down. Further, the main frame 10 is provided with a servo motor 30, and a ball screw 31 is connected to a rotation shaft of the servo motor 30. The subframe 20 is provided with a nut portion 21 that is screwed into the ball screw 31. Therefore, when the ball screw 31 is rotated by driving the servo motor 30, the sub frame 20 moves up and down with respect to the main frame 10. Note that linear guides (not shown) are arranged on both sides of the ball screw 31, and the subframe 20 moves up and down while being guided by the linear guides. In addition, the servo motor 30 incorporates an encoder for detecting the rotation amount and rotation speed of the servo motor 30 and detecting the vertical position of the sub-frame 20 with respect to the main frame 10.

  A nozzle unit 40 is mounted on the subframe 20 so as to be vertically movable in the Z direction and rotatable about the Z axis (θ direction). In the present embodiment, a total of 12 nozzle units 40 are mounted in one row in the X direction. At the lower end of each nozzle unit 40, a nozzle 41 that holds and holds the electronic component in a releasable manner is mounted.

  In addition, a shaft type linear motor 50 is fixed to the sub frame 20 at a position vertically above each nozzle unit 40 in order to individually move each nozzle unit 40 up and down with respect to the sub frame 20. Each shaft type linear motor 50 has a built-in linear encoder for detecting the vertical position of each nozzle unit 40 with respect to the subframe 20.

  Further, the sub frame 20 is provided with a rotating device 60 for rotating the nozzle unit 40 around the Z axis (θ direction). In the present embodiment, the rotating device 60 includes two motors 61 so that the six nozzle units 40 are rotated by one motor 61. Specifically, timing belts 62 are wound around six nozzle units 40 for one motor 61, and each nozzle unit 40 is rotated around the Z axis (θ direction) by rotating the motor 61. Rotate to.

  Next, the configuration of the nozzle unit 40 will be described. FIG. 3 is a front view showing the nozzle unit 40 and the shaft-type linear motor 50 disposed vertically above it as a single unit.

  The nozzle unit 40 is mainly composed of a ball spline 42, and the ball spline 42 is rotated around the Z axis (θ Direction).

  The nozzle 41 is attached to the lower end of the spline shaft 42a, moves in conjunction with the sliding of the spline shaft 42a in the Z direction, and is displaced up and down with respect to the subframe 20. A coil spring 44 is mounted around the spline shaft 42 a, the upper end of the coil spring 44 is fixed to the upper end portion of the spline shaft 42 a, and the lower end of the coil spring 44 is fixed to the subframe 20. Therefore, if no external force is applied to the spline shaft 42a, the spline shaft 42a and the nozzle 41 attached thereto are biased upward by the elastic force of the coil spring 44. On the other hand, when a force that presses the spline shaft 42 a downward is applied, the spline shaft 42 a and the nozzle 41 move downward against the elastic force of the coil spring 44. The coil spring 44 functions as a biasing unit that biases the nozzle 41 upward with respect to the subframe 20.

  Note that if the spring length of the coil spring becomes too large with respect to the spring winding diameter, the coil spring tends to buckle when compressed, and the buckled spring part may interfere with other parts. Therefore, the coil spring 44 is divided into two stages in the Z direction by the spacer 44a, and the spring length is secured without increasing the spring winding diameter. Thereby, when the nozzle unit 40 is disposed close to each other, it is possible to prevent the buckled coil springs 44 from interfering with each other.

  The shaft-type linear motor 50 disposed vertically above the nozzle unit 40 includes a motor main body 51 fixed to the subframe 20 and a shaft 52 that is slidable in the vertical direction with respect to the motor main body 51. Since the detailed configuration of the shaft type linear motor is known, the description is omitted.

  The tip of the shaft 52 of the shaft type linear motor 50 is connected to the spline shaft 42 a via a bearing 45. Therefore, when a downward thrust is generated on the shaft 52, a pressing force acts on the upper end of the spline shaft 42a via the bearing 45. When this pressing force exceeds the elastic force of the coil spring 44, the spline shaft 42a moves downward, and the nozzle 41 attached to the lower end of the spline shaft 42a moves downward relative to the subframe 20. Further, since the shaft 52 is connected to the spline shaft 42 a via the bearing 45, the shaft 52 is not affected by the rotation of the ball spline 42.

  Next, the operation when the nozzle 41 is moved up and down in the mounting head 100 of the present embodiment will be described in comparison with the conventional technique of Patent Document 1. 4A shows a state in which the nozzle 41 is positioned at the upper limit starting position in the mounting head 100 of the present embodiment, and FIG. 4B shows a state in which the nozzle 41 is moved downward. 4C shows the mounting head 200 of Patent Document 1 in which the nozzle 202 is moved up and down only by the shaft type linear motor 201, and the nozzle 202 is moved downward with the same stroke as in FIG. 4B. Indicates the state of the

  In the mounting head 100 of this embodiment. In addition to moving the nozzle unit 40 up and down by the shaft type linear motor 50 fixed to the sub frame 20, the sub frame 20 is moved up and down by the servo motor 30, so that the stroke of the shaft type linear motor 50 is not increased. By moving the subframe 20 up and down, the stroke of the nozzle 41 can be increased as shown in FIG.

  On the other hand, in the mounting head 200 of Patent Document 1 shown in FIG. 4C, if the same stroke as in FIG. 4B is to be obtained, the stroke of the shaft type linear motor 201 needs to be increased accordingly. As shown in FIG. 4C, the shaft type linear motor 201 is increased in size up and down. As a result, as described above, the position of the center of gravity of the mounting head 200 is increased, and the mounting head 200 is likely to vibrate, and the nozzle 202 also vibrates accordingly. Further, when the nozzle stroke is increased in the mounting head 200, the spline shaft 203 of the ball spline greatly extends downward from the held portion as shown in FIG. This causes the problem that the mounting accuracy is lowered.

  In the mounting head 100 of the present embodiment, as described above, the stroke of the nozzle 41 can be increased without increasing the stroke of the shaft-type linear motor 50, leading to an increase in the size of the mounting head and a decrease in mounting accuracy. In addition, the nozzle stroke can be increased.

  As described above, in the electronic component mounting method using the mounting head according to the present embodiment, the combination of the vertical movement of the sub-frame 20 by the servo motor 30 and the vertical movement of the nozzle unit 40 by the shaft type linear motor 50 is used. 41 is moved up and down.

  A specific example will be described with reference to FIG. 5A shows the vertical position of the nozzle 41 in each process, FIG. 5B shows the stroke of the servo motor 30 in each process, and FIG. 5C shows the shaft type linear motor in each process. 50 strokes are shown. That is, the vertical position of the nozzle 41 in FIG. 5A is defined by the sum of the stroke of the servo motor 30 in FIG. 5B and the stroke of the shaft type linear motor 50 in FIG.

  In FIG. 5, the position A indicates a state in which the nozzle 41 is positioned at the upper limit starting position. At this time, both the servo motor 30 and the shaft type linear motor 50 are at the upper limit starting position and the stroke is zero. .

  In FIG. 5, the position B indicates a state when the electronic component is picked up by the nozzle 41 and then picked up by the camera unit of the mounting head. At this time, the servo motor 30 has a stroke = 0 and uses only the stroke of the shaft type linear motor 50.

  In FIG. 5, a position C indicates a state when the electronic component is mounted on the substrate by the nozzle 41. At this time, the servo motor 30 and the shaft type linear motor 50 are used in combination.

  In FIG. 5, a position D indicates a state when the nozzle 41 is removed when the nozzle 41 is replaced. Also at this time, the strokes of the servo motor 30 and the shaft type linear motor 50 are used in combination. At this time, the stroke of the servo motor 30 is the maximum.

  In FIG. 5, the position E indicates a state when the nozzle 41 is newly attached after the nozzle 41 is removed. Also at this time, the strokes of the servo motor 30 and the shaft type linear motor 50 are used in combination. At this time, the strokes of the servo motor 30 and the shaft type linear motor 50 are both maximum.

  The combination of the strokes of the servo motor 30 and the shaft type linear motor 50 shown in FIG. 5 is merely an example, and it is obvious to those skilled in the art that they can be used in appropriate combinations according to the specifications of the mounting apparatus.

DESCRIPTION OF SYMBOLS 1 Base 2 Board | substrate 3 Board | substrate conveyance apparatus 4 Parts feeder 5 Y table 6 X table 7 Camera 10 Main frame 20 Sub frame 21 Nut part 30 Servo motor 31 Ball screw 40 Nozzle unit 40a Pulley 41 Nozzle 42 Ball spline 42a Spline shaft 43 Bearing 44 Coil spring 44a Spacer 45 Bearing 50 Shaft type linear motor 51 Motor body 52 Shaft 60 Rotating device 61 Motor 62 Timing belt 100, 200 Mounting head 201 Shaft type linear motor 202 Nozzle 203 Spline shaft

Claims (2)

In an electronic component mounting apparatus comprising a mounting head for mounting a plurality of electronic components on a plurality of mounting locations on a printed circuit board by adsorbing and holding a plurality of electronic components by a plurality of nozzles,
The mounting head is
The mainframe,
A subframe provided to be movable up and down with respect to the main frame;
A servo motor provided on the main frame and moving the sub frame up and down;
A plurality of nozzle units that are mounted at the lower end of the nozzle and are movable up and down with respect to the sub-frame;
A plurality of shaft-type linear motors that are fixed to the sub-frame vertically above each nozzle unit and individually move the nozzle units up and down relative to the sub-frame;
An electronic component mounting apparatus, comprising: a rotation device provided on the subframe and configured to rotationally drive each of the nozzle units. In the electronic component mounting method by the electronic component mounting apparatus according to claim 1,
An electronic component mounting method, wherein each nozzle is moved up and down by a combination of the vertical movement of the sub-frame by the servo motor and the vertical movement of each nozzle unit by each shaft type linear motor. .

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