JPH03203294A - Mounting apparatus for electronic component - Google Patents

Abstract

PURPOSE:To shorten the time required to mount components by a method wherein two sets of head-moving bodies equipped respectively with component- mounting heads are installed and the components are mounted while the individual head-moving bodies are advanced and retreated alternately from both sides with reference to a componentmounting region. CONSTITUTION:While a head unit Uh on the back side recognizes an image of a component suction state, a head unit Uh on the front side picks up two electronic components to be mounted from a component supply cassette 26B on the front side in the same action as the head unit Uh on the back side. When the head unit Uh on the back side has recognized the image of the components, it is moved to a mounting position on a work station Ws which executes a component-mounting operation. That is to say, the electronic components are mounted on one printed-circuit board alternately from both sides by using the two head units Uh, Uh. Thereby, the mounting time can be shortened to about a half as compared with a case where the components are mounted by using one head unit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronic component mounting apparatus for mounting chip-shaped electronic components on a substrate.

[Prior art and its problems]

Conventionally, the following X-Y movement mounting equipment is well known as an electronic component mounting equipment designed to automatically mount a large number of chip components such as IC1 resistors and capacitors on a printed circuit board at high speed and with high precision. It is being

A pair of guide rails is laid across a work station on which parts are mounted, and a support body for supporting a mounting head is slidably installed between the guide rails. Each support supports the mounting head slidably in a direction perpendicular to the guide rail. That is, the mounting head is supported so as to be freely movable in two dimensions: the direction along the support body (referred to as the X direction) and the direction along the guide rail (referred to as the Y direction).

When mounting components, the mounting head picks up the components to be mounted from the component supply section, then quickly moves in the X-Y two-dimensional direction and advances to the component mounting position on the printed circuit board positioned on the work station. , and place the picked-up electronic components thereon. After placing the electronic components,
Return to the component supply position again and move on to picking up the next electronic component to be mounted. By repeating this series of operations, various types of electronic components are mounted on the printed circuit board.

In the above-mentioned mounting device, the weight of the head moving body consisting of the mounting head, its drive mechanism, and the support that supports them is
necessarily become larger. When such a heavy head moving body is moved at high speed in order to increase the mounting speed of electronic components, it is difficult to brake it smoothly and accurately position it at the target position, resulting in a decrease in component mounting accuracy. invite. Therefore,
In order to ensure the required mounting accuracy, it is required to suppress the moving speed of the head moving body below a certain limit. As a result, it becomes difficult to increase the mounting speed of electronic components to a desired level.

[Purpose of the invention]

The present invention has been made in view of the problems of the prior art described above, and provides an electronic component mounting device that can mount many types of electronic components at high speed and with high precision without excessively increasing the moving speed of the mounting head. The purpose is to

[Key points of the invention]

In order to achieve the above-mentioned object, the present invention includes: a working head that can move up and down relative to an electronic component and hold the electronic component in a detachable manner; a head driving means that slidably supports the working head and moves it back and forth; An electronic component mounting apparatus comprising: a head support that supports the work head and the head drive means so as to be integrally movable; and a support drive means that moves the head support body forward and backward with respect to a component mounting work area,
Two sets of component mounting mechanisms each comprising the working head, the head driving means, the head support and the support driving means are provided, and each of the support driving means has a pair of parts mounting mechanisms connected to both ends of each of the head supports. The key point is that the transport member is comprised of a conveying member and a connecting member that connects the pair of conveying members so that they can be driven synchronously.

[Embodiments of the invention]

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 and 2.

FIG. 1 is a plan view showing an electronic component mounting apparatus as an embodiment of the present invention, and FIG. 2 is an elevational view thereof. In Figure 1,
A substrate conveyor 2 for conveying printed circuit boards is laid horizontally extending from the center of the device base 1 in the lateral direction (hereinafter referred to as the X direction) in the figure. The substrate conveyor 2 has a pair of rails 2a+2a laid in parallel on both sides, and a pair of conveyor bells 2b and 2b each stretched so as to run on each rail 2a. These conveyor belts 2b, 2b are
It is driven by a substrate transport motor 3 placed at an appropriate location. The printed circuit board pb on which components are to be mounted is supported on both sides by transport bells) 2b, 2b, respectively, and as it rotates, the printed circuit board pb moves onto the rail 2.
It is conveyed from the right side in the figure along the direction of arrow T while being guided by a+2a.

A work station Ws on which electronic components are mounted is set up approximately at the center of the device base 1 on the travel path of the substrate conveyor 2. This work station Ws is defined by rails 2a, 2a on both sides, and positioning pins 4a, 4b at the front end and rear end with respect to the substrate transport direction T, respectively. Both positioning pins 4a and 4b are rotatably supported, respectively, and are rotated by a driving means such as an air cylinder (not shown) to advance their tips into the substrate transport path, and are moved by the transport belts 2b and 2b. Printed circuit board p being transported
Stop b.

Fixing tables 5a and 5b are installed at the front and rear ends of the apparatus, respectively, across the work stage Ws, so as to straddle the substrate conveyor 2. Each fixing table 5at5b is fixed and extends in a direction (hereinafter referred to as Y direction) perpendicular to the substrate conveyance direction (X direction). These fixed stands 5a, 5
A pair of guide rails E3a and 6b are laid on the guide rails E3a and 6b. These guide rails 6a+8b are laid along the inner sides (work station Ws side) of the fixed bases 5a+5b so as to extend in the Y direction.

Between the pair of guide rails 6a + 6b, there are two moving platforms 7.
A and 7B are installed so that they can slide freely. As will be described later, each of these movable tables 7A and 7B reciprocates between predetermined areas on the rear side (upper side in the figure) and the front side (lower side in the figure) of the apparatus. Each moving platform 7A, 7B has both ends attached to each guide rail 8a+eb with a pair of sliding bearings 8, respectively.
, 8 is slidably extrapolated. In this case, a pair of sliding bearings 8 are interposed at the ends of each moving platform 7A, 7B.
, 8, one interval DI is set larger than the other interval D2. The reason for this is mobile platform 7A.

The relationship with each driving means of 7B will be explained later. Each moving platform 7
On A and 7B, X-axis ball screws 9 and 9 are installed along the longitudinal direction (X direction), respectively.

A servo motor 11 is connected to one end of each X-axis ball screw 9 via a coupling 10.

Further, a guide rod 12 is installed parallel to each X-axis ball screw 9. This guide rod 12 slidably supports a head unit Uh, which in this example is provided with two mounting heads 13.13.

As shown in FIG. 2, each mounting head 13 is equipped with a suction nozzle 13a facing vertically for sucking electronic components with air. Each head unit Uh has two mounted heads 1
3.13 is attached by integrally movably coupled with a plate 14, and this attachment is accomplished by slidingly inserting the plate 14 onto the guide rod 12. The plate 14 is attached to a feed base 15 installed on the X-axis ball screw 9 so as to be movable in a reciprocating manner. The feed table 15 and the X-axis ball screw 9 are connected via a nut member 16 screwed onto the X-axis ball screw 9.

By operating the servo motor 11 and rotating the X-axis ball screw 9 in both forward and reverse directions, the feed table 15 and head unit U are rotated.
h can be integrally moved in a reciprocating straight line along the guide rod 12. In this case, the ball screw has characteristics such that the frictional resistance between the screw and the nut is small and backlash can be easily removed, so that high-speed movement and high-precision positioning of the mounting head 13 are possible.

On the above-mentioned pair of front and rear fixed bases 5a+5b, Y-axis drive ball screws 1 are installed parallel to the guide rails 8a and f3b, respectively.
7 all 7 +) is installed. A pair of Y-axis drive ball screws 17a, 17b are connected to the upper region (
It covers an area of approximately 375 mm from the central area to one end. In this case, the pair of Y-axis drive ball screws 17a, 17b extend from respective central regions on the front and rear fixed bases 5a, 5b to mutually opposite ends. In this example, the Y-axis drive ball screw 17a installed on the front side with respect to the board transport direction T is placed in the back area on the front fixing table 5a, and the Y-axis drive ball screw 17b installed on the rear side is placed on the rear fixing table 5b. They each extend to the front side area. And these Y-axis drive ball screws 17 a, 17 b
Couplings 18a, 18 are provided at each center end of the
The Y-axis drive servo motors 19a and 19b are connected via b.

On the other hand, on each inner surface of the front and rear fixed bases 5a+5b,
Y-axis drive ball screws 20a and 20b are installed. In this case, the Y-axis drive ball screw 20a installed on the front side faces the Y-axis drive ball screw 17b on the rear side, and the Y-axis drive ball screw 20b installed on the rear side faces the Y-axis drive ball screw 17a on the front side in parallel. This is an extended installation. Then, the Y-axis drive ball screw 2 facing on the front side of the device
Toothed pulleys 21a and 21b are fixed to the ends of the drive ball screw 0a and the Y-axis drive ball screw 17b on the front side of the device, respectively. Below each of the toothed pulleys 21a and 21b, as shown in FIG. 2, pulleys 21c and 21d, which are two toothed pulleys arranged coaxially in parallel, are rotatably installed. A toothed belt 22 al 22 is connected between these two toothed pulleys 21a and 21b and the two relay pulleys 21C92id.
b + 22 c, both ball screws 20a, 1
7b are connected for synchronous rotation. By detouring the drive transmission path between both ball screws 20a and 17b downward in this manner, members such as the component supply cassette 26, which will be described later, can be easily attached and detached from the front side of the apparatus.

Similarly, a toothed pulley 23a is connected between the Y-axis driving ball screw 17a and the Y-axis driven ball screw 2Ob, which face each other on the back side of the device.
, 23b, etc., and are connected to each other for synchronous rotation by a toothed bell) 24c, etc.

9-0- Therefore, the Y-axis drive ball screw 17a facing on the back side of the device
The Y-axis drive ball screw 20b and the Y-axis drive ball screw 20b, which face each other in front of the device, are attached to both ends of the back side moving table 7A.
The shaft drive ball screws 17b are threadedly connected to both ends of the front side moving table 7B via nut members 25, respectively. In this case, each of the Y-axis drive ball screws 17a, 17b is connected to the end of each end of the movable bases 7A, 7B, where the spacing between the sliding bearings 8°8 described above is set to the large spacing DI. It is.

Therefore, if the Y-axis drive motor 19b connected to the Y-axis drive ball screw 17b is operated, the toothed bells) 22a to 2
The Y-axis drive ball screw 17b and the Y-axis drive ball screw 20a connected by 2c rotate synchronously, and a long head moving body HB consists of a moving table 7B on the near side and a pair of mounting heads 13 and 13 supported by this. moves in the Y direction along the guide rails 6a, 6b. In this case, head moving body HB
are the Y-axis drive ball screw 17b and the Y-axis drive ball screw 2.
0a freely reciprocates in the area in which they extend oppositely, that is, in the approximately 875 area on the near side including the above-mentioned work stage gin Ws above the base body 1. On the other hand, the head moving body HA on the back side of the device also
Similarly, the Y-axis drive ball screw 17a and the Y-axis drive ball screw 20b rotate synchronously with the operation of the Y-axis drive motor 19a, and freely reciprocate in about 375 areas on the back side including the work stage a7Ws. Therefore, both head moving bodies HA.

Each moving area of HB is located at the work stage W in the center of the device.
They overlap in the end region (region above the substrate transport path) including s.

Incidentally, it is possible to cause the head moving bodies HA and HB to move in a reciprocating straight line by applying a driving force from only one side, but in the present invention, the driving force is applied from both sides as described above. . The reason is as follows.

Each head moving body HA,) IB has a pair of mounting heads 13
．． 13 so as to be movable in a predetermined direction (X direction), and various members such as a driving means are mounted on a moving table 7A.

Since it is supported on 7B, it is naturally long and heavy as a whole. Such a head moving body HA.

) (If B is moved by applying driving force only from one end, the moment of inertia is large, so the non-drive end of each head moving body HA and HB will vibrate violently, especially when starting or stopping. Therefore, for example, one of the head moving bodies HA
Not only the positioning accuracy of the head moving body HB itself is reduced, but also the vibration is transmitted to the other head moving body HB via the guide rails 6a+6b, and the positioning accuracy of the other head moving body HB is also reduced.

Therefore, in the present invention, as described above, ball screws 17a, 20b and ball screws 17b, 20a as driving means are connected to both ends of the head moving bodies HA, HB, respectively, and linear driving force is applied approximately equally from each end. to act. Thereby, even the long and heavy head moving bodies HA and HB can be smoothly moved in the Y direction without vibration and accurately positioned.

In addition, in order to more stably suppress the occurrence of vibration in each of the head moving bodies HA and HB, in this example, sliding bearings 8 and 8 on the driving side are used.
The distance Di is set larger than the distance D2 for the sliding bearing on the driven side. Thereby, the ball screws 17a, 20b and 17b, 2 on both sides that drive the head moving bodies HA, HB.
Even when the timings of the operations 0a are shifted, vibrations of the head moving bodies HA and HB can be effectively suppressed.

As a result, the head moving bodies HA and HH can be stably positioned with high precision.

Furthermore, for example, if we explain using the head moving body HB on the near side,
Each ball screw 20a, 17b is brought close to a pair of guide rails 6a, 8b that support both ends of the head moving body HH,
In addition, since it is laid behind them (with respect to the substrate transport direction T), the bending moment I. generated by the linear driving force acting on the head moving body HB is reduced. Thereby, the rigidity of the moving table 7B and the like in the head moving body HB can be reduced, and the size and weight of the apparatus can be reduced.

On the base 1, component supply units FA and F are located near the ends of the base on the back and front sides of the board conveyor 2.
B is set respectively. Each parts supply department FA, FB has
A large number of component supply cassettes 3-4-261.28B are set in parallel. Parts supply cassette 2E! Both A and 26B are tapes in which, for example, rectangular parallelepiped chip components are embedded at regular intervals and wound around a reel. Each parts supply cassette) 26A,
The same electronic components are stored in each of the cassettes 26B, and by arranging a large number of component supply cassettes 28A and 26B in parallel, it is possible to prepare a large amount of various types of electronic components. In this case, the permutations and combinations of the types of electronic components (component supply cassettes) are optimally set so that components can be supplied efficiently in as short a time as possible. In this example, the component supply cassette (2) that stores large electronic components is placed in the component supply position FB on the front side.
13B, and a component supply cassette 26A containing small electronic components is set in the component supply position FA on the back side. When supplying parts, the supply tape is intermittently fed out from the reel by the equipped feeding mechanism, and the supply tape is moved to the pick-up position P.
The suction nozzle 1 of the mounting head 13 that has descended at p
3a (Fig. 2).

A pair of image recognition cameras 27A, 27A and 27B, 27B and suction nozzle exchangers 28A, 2813 are installed between each component supply position FA, FB on the back side and front side of the device and the substrate conveyor 2, respectively. It is installed.

Each of the image recognition cameras 27A to 27B is mounted on the mounting head 13.
An image of the electronic component suctioned by the suction nozzle 13a is taken, and the image is processed by a computer to detect a deviation in the suction position. This detection data is sent to a central control unit (not shown) and is used for position correction when mounting the electronic component on the printed circuit board pb. In this example, each head moving body HA
, since two mounting heads 13 and 13 are installed in parallel on each HB, correspondingly two image processing cameras 2 are installed on each HB.
7A, 27A and 27B, 27B are arranged in parallel at each predetermined position.

The suction nozzle exchangers 28A and 28B each form a large number of storage bits in parallel, and hold suction nozzles 13a of other types in these storage pits in preparation for replacement. The installation positions of the image recognition cameras 27A to 27B and the suction nozzle exchangers 281 and 28B described above are optimally set so that the total mounting time of electronic components can be shortened as much as possible.

All the drive means in the electronic parts replacement device, i.e.
Axis drive motor 11, 11, Y-axis drive motor 19 a+
19 bs A motor 3 for driving each board conveyor, an air cylinder for lifting and lowering the mounting head 13 and for suction (not shown), a feeding mechanism for the component supply tape, etc., and a camera 271 for image processing.
~27B are connected to a central control unit (not shown) of an electronic component replacement device, and an optimal control signal based on a preset program is output from the central control unit to each drive means, so that the electronic components can be efficiently and quickly replaced. It is mounted on the printed circuit board PB on time and accurately. The basic pattern of the component mounting operation will be explained below.

First, it is assumed that an electronic component is picked up by the rear mounting head 13, for example. A head unit Uh equipped with a pair of mounting heads 13.13 is connected to a Y-axis drive motor 19a and an X-axis drive motor 19a.
While operating the shaft drive motor 11 to move in the X direction,
It is also moved in the direction and stopped above the pickup position Pp of the component to be picked up in the component supply case throat 213A. Next, the head unit Uh is lowered to pick up the two target parts at the same time, and then raised.

In addition, if two target parts cannot be picked up at the same time due to the arrangement of the parts supply cassette 28A, the head unit 1-U
Move h in the X direction and pick them up one by one.

Next, in order to detect a suction position shift, the head unit Uh that has suctioned the target component is moved above the image processing camera 27A, and image recognition of the component suction state is performed. The suction position data detected by image recognition is sent to the central control unit.

When the head unit Uh on the back side performs image recognition of the component suction state, the head unit Uh on the front side picks up two parts from the front side component supply case y)2EiB to the back side head unit)Uh in the same manner as the head unit Uh on the front side. Pick up the electronic components that should be installed.

After completing the image recognition of the parts, the back head unit Uh moves to the mounting position on the work stage aWS where parts are to be mounted. At this time, the central control section corrects the stop position of the head unit Uh based on the suction position shift data obtained in the previous image recognition step, and the head unit Uh stops at the corrected mounting position. The work station Ws has a board conveyor 2.
Along with the rotation, the printed circuit board Pb is transported and positioned at a predetermined position.

Immediately after the positioning is completed, the head unit Uh descends and places the two electronic components at predetermined positions on the printed circuit board Pb.

After the parts have been placed by the back head unit Uh,
Next, parts are placed by the front head unit Uh. At this time, as mentioned above, each head moving body) (A
Since the movement ranges of the head moving bodies HA and HB overlap in the central region including the work station Ws, there is a possibility that the head moving bodies HA and HB will collide with each other.

In this example, each Y-axis drive motor 19a, 19b is provided with an encoder section, and the pulse signals from this encoder section are counted by the central control section to drive each head moving body HA, HB.
I know the location of. Then, each Y-axis drive motor 19a confirms the relative position of both head moving bodies HA and HB based on the position data.

19b to prevent the head moving bodies HA and HB from colliding with each other on the work station Ws.

The back head unit Uh, which has finished placing the components and retreated from the work station Ws, heads again to the component supply position FA in order to pick up a new electronic component to be mounted. Here, if it is necessary to replace the suction nozzle 13a for the next electronic component to be mounted, the head unit Uh is moved above the suction nozzle exchanger 28A, and the suction nozzle 13a is replaced. In this case, first, the suction nozzle 13 used
After storing a into the designated storage pit, a new suction nozzle is installed. The suction nozzle 13a is automatically attached and detached by raising and lowering the head unit Uh.

The back head unit Uh has returned to the parts supply position FA.
Start picking up new electronic parts. At this time, the front head unit (Uh) is mounting components onto the printed circuit board pb. After that, two head units U
b and Uh repeat similar operations, and electronic components are mounted on the printed circuit board Pb in an orderly and rapid manner.

As mentioned above, electronic components are mounted alternately from both sides on one printed circuit board pb using the two head units Uh and Uh, so the electronic components are mounted on one printed circuit board pb by half compared to when mounting with one head unit. Loading time is reduced. As a result, it is possible to eliminate the disadvantage of the mounting position correction method using image recognition, that is, the disadvantage that image processing takes time and the mounting time is extended. Therefore, by adopting the mounting position correction method based on image recognition, the accuracy of the mounting position of electronic components can be greatly improved, and the mounting speed of electronic components can be increased.

It should be noted that the present invention is not limited to the specific embodiments described above, and it goes without saying that various modifications can be made within the technical scope of the present invention.

For example, the drive means for moving the head unit Uh is not limited to a combination of a motor and a ball screw, but can also employ various drive and speed change mechanisms, such as a mechanism that converts the rotational force of a motor into linear motion using a pinion and a rack. .

Further, the linear guide means such as the guide rails E3a and f3b are not necessarily required, and can be omitted by increasing the rigidity of the drive means such as a ball screw.

Furthermore, the position correction of the electronic component suction position is not performed by an optical method using an image recognition camera as in the above embodiment, but by a mechanical method in which chuck claws are provided on all sides of the suction nozzle to hold it evenly from all sides. It is also possible. Alternatively, the suction nozzle exchanger 26 may not be installed, and the suction nozzle exchanger 26 may be replaced manually as required.

In addition, the present invention can also be applied to a method in which printed circuit boards are not continuously conveyed linearly but are conveyed intermittently in spots.

〔Effect of the invention〕

As described in detail above, according to the present invention, two sets of head moving bodies each having a component mounting head are provided, and each head moving body is moved alternately forward and backward from both sides of the component mounting area to mount the component. Since the work is carried out, it is possible to quickly and orderly mount a wide variety of electronic components onto a board, and the total time required for component mounting is significantly shortened. Since the driving means of each head moving body is connected to both ends, it is possible to accurately control the stopping position of the head moving body, which tends to be a long and heavy body, and to improve the accuracy of the mounting position of electronic components. It is possible to raise it.

In addition, since the driving force is applied equally to the head moving body from both ends, almost no crushing moment is applied to the head moving body, and the loading time can be shortened as described above without excessively increasing the moving speed of the mounting head. Can be shortened. Therefore, there is no need to increase the strength of each part of the device, and there is no need to use a high-output motor as a drive source, so it is possible to reduce the size and weight of electronic component mounting devices with short mounting time and high mounting position accuracy. This makes it possible to provide the product at a low cost.

In addition, if the electronic component mounting apparatus of the present invention adopts a method of correcting the suction position of electronic components using image processing, the mounting time for electronic components will not be increased even if image processing takes time, and the mounting position accuracy can be significantly improved. can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an electronic component mounting apparatus as an embodiment of the present invention, and FIG. 2 is an elevational view of the electronic component mounting apparatus. 1... Base 2... Board conveyor 5a, 5b... Fixed base 8a, eb... Guide rails 7A, 7B... Moving platform 8... Sliding bearing 9... X-axis ball screw 11...X-axis drive motor 12...Guide rod 3...Work head 13a...Suction nozzles 17a, 17b...Y-axis drive ball screws 19a, 19
b...Y-axis drive motors 20a, 20b...Y-axis drive ball screws 21a, 21
b, 23a, 23b... toothed pulleys 21c, 21d
...Relay pulleys 22a to 22 C124c...Toothed belt 25...
・Nut members 26A, 28B...Parts supply cassettes 27A, 27B
... Image recognition camera 28A, 28B ... Suction nozzle exchanger pb ... Printed circuit board HA, HB ... Head moving body Uh ... Head unit Ws ... Work station Shiron Pp ... Pick-up position 25-

Claims (1)

[Claims] a working head capable of moving up and down relative to the electronic component and holding the electronic component in a detachable manner; a head driving means for slidably supporting the working head and reciprocating the working head; and moving the working head and the head driving means integrally. In the electronic component mounting apparatus, the electronic component mounting apparatus has a head support that can support the head support, and a support drive means that moves the head support body forward and backward with respect to a component mounting work area, the work head, the head drive means, and the head. Two sets of component mounting mechanisms each including a support and the support drive means are provided, and each of the support drive means synchronously drives a pair of transport members connected to both ends of each head support and the pair of transport members. An electronic component mounting device characterized by comprising a connecting member that can be connected together.