JP2002261494A - Automatic component mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic component mounting method is which a component can be mounted accurately at a mounting position even in such a case as the component is recognized during acceleration of a component suction head. SOLUTION: In the automatic component mounting method, the component is sucked through the suction nozzle of a component suction head and moved to a mounting position before being mounted. Movement data of the part suction head required for mounting the component at the mounting position is subjected to correction for the suction error of the component and correction for the positional error of recognition caused by an acceleration applied to the component suction head. Based on the corrected movement data, the component suction head is moved by a required amount and then the component is mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for sucking a component at a suction position by a suction nozzle provided in a component suction head.
The present invention relates to an automatic component mounting method in which a component suction head is moved to a mounting position as it is moved, and the operation of releasing the suction at the mounting position and automatically mounting the component is performed.

[0002]

2. Description of the Related Art As an automatic component mounting method, a component (for example, an electronic component such as an IC, a chip-type resistor, or a capacitor) is suctioned at a suction position by a suction nozzle provided below a component suction head. In some cases, the head is moved to a mounting position (for example, a designated position on a printed circuit board) as the head is moved, and the work of releasing the suction at the mounting position and mounting is automatically performed. Here, the position of the component sucked by the suction nozzle with respect to the suction nozzle (hereinafter, the shift amount of the component position with respect to the center of the suction nozzle is referred to as a suction shift amount) is slightly different each time suction and mounting are performed. This is because the direction and the position of the components in the component supply container arranged at the suction position slightly differ from each other. As described above, since the amount of suction deviation is slightly different each time, in order to properly mount the component at the mounting position, the moving amount of the component suction head from the time when the component is suctioned to the time when the component is mounted is determined according to the amount of suction deviation. Need to be adjusted. Conventionally, in order to perform such adjustment of the movement amount,
For example, the amount of suction deviation is recognized using a line sensor, the movement amount (or the stop position at the time of mounting) of the component suction head is corrected by the recognized deviation amount, and the component is corrected by the movement amount obtained as a result of this correction. The suction head is moved to mount components. Here, the measurement of the suction deviation amount is performed in a process of moving the component to the mounting position after the component is suctioned by the suction nozzle. This is to improve work efficiency. For a more specific conventional automatic component mounting method, refer to, for example, JP-A-6-252598.

[0003]

However, since the component suction head is not a completely rigid body, "bending (bending)" occurs during acceleration / deceleration accompanying movement. On the other hand, when the component is mounted at the mounting position, the component suction head is in a stopped state, so that at this point, the bending generated during acceleration / deceleration is also eliminated. Therefore, as in the related art, when the movement amount of the component suction head is calculated based on the suction shift amount recognized during acceleration and deceleration of the component suction head, and the component is mounted by moving the component suction head based on the calculated value, There is a problem that the mounting position of the component is shifted. That is, there is a case where the component cannot be accurately mounted at the mounting position only by correcting the movement amount of the component suction head by the amount corresponding to the suction shift amount as in the related art.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and can accurately mount a component at a mounting position even when component recognition is performed during acceleration / deceleration of a component suction head. An object is to provide an automatic component mounting method.

[0005]

According to a first aspect of the present invention, a component is sucked at a suction position by a suction nozzle provided in a component suction head, and the component suction head is moved. In the automatic component mounting method in which the component is moved to the mounting position, and the component is released at the mounting position and released by suction, the movement data of the component suction head necessary for mounting the component at the mounting position is compared with the component data. In order to correct the suction error and mount the device at the mounting position, during the movement, the position of the component with respect to the reference position is recognized by component recognition means, and not only the correction based on the recognized position of the component is performed, but also the correction is performed. In order to correct the error of the recognition position caused by the acceleration applied to the component suction head for movement and mount the component at the mounting position, a correction based on the acceleration of the component suction head at the time of component recognition is also performed. And it is characterized in that these corrected by moving a required amount of component suction head based on the movement data has been subjected to mounting the parts.

According to the first aspect of the present invention, not only the correction based on the position of the component with respect to the reference position recognized during the movement, but also the correction based on the acceleration of the component suction head at the time of component recognition is performed. Is obtained, the component suction head is moved by a required amount based on the movement data, and the component is mounted. As a result, a component based on movement data that has been deviated from a value necessary for accurately mounting the component at the mounting position due to bending generated in the component suction head during acceleration and deceleration due to movement. There is no need to move the suction head. Therefore, even if the component recognition is performed during acceleration / deceleration of the component suction head, the component can be accurately mounted at the mounting position.

Further, the present invention is characterized in that the recognition is performed by moving the component recognizing means integrally with the component suction head, as in the second aspect of the present invention. In this case, the shift amount of the movement data due to the bending generated in the component suction head is reduced in the first place, but the shift amount is corrected. Alternatively, the present invention is characterized in that the recognition is performed by the fixed component recognition means, for example, as in the invention described in claim 3. In this case, since the component recognizing means is not moved integrally with the component suction head, the driving force for moving the component suction head is small, and the mechanical strength of the driving mechanism is small. Therefore, a relatively compact configuration can be obtained.

Further, corrected movement data (movement data)
May be data relating to the stop position of the component suction head or data relating to the amount of movement. Further, the acceleration of the component suction head at the time of component recognition may be obtained, for example, by reading a value stored in advance in a table corresponding to the movement time of the component suction head based on the movement time of the component suction head. Alternatively, it may be obtained by calculation based on the moving distance and moving time of the component suction head, or may be obtained by measuring with an acceleration sensor.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The automatic component mounting apparatus 100 shown in FIG. 1 mounts a rectangular component 60 (FIG. 5) taken out from a component supply unit by suction at a designated position on a printed circuit board. Is moved in the X-axis direction, and the Y-axis motor 2 drives the Y-axis.
A component transfer frame 10 that is moved in the axial direction is provided. The component transport frame 10 is provided with a head unit 11 that is moved in the X direction. The head unit 11 is provided with a component suction head 20, and the component suction head 20 is provided with a suction nozzle 30 fixed to a lower end thereof. (FIG. 3). The suction nozzle 30 has a suction portion 31 at the lower end thereof.
The component 60 (FIG. 5) is attracted by the negative pressure.

The component suction head 20 is movable with respect to the head portion 11 of the component transport frame 10 in the Z-axis direction (vertical direction) and the θ-axis direction (rotation direction around the Z axis). That is, as shown in FIG. 3, the component suction head 20
-Axis motor 21 for moving up and down, and Z-axis motor 2
1 is provided with a ball screw 23 that rotates in accordance with the driving of the motor 1. On the other hand, with the rotation of the ball screw 23, the component suction head 20
Is held by a vertically moving frame 25 that moves up and down. Accordingly, the component suction head 20 moves up and down with respect to the head unit 11 as the Z-axis motor 21 is driven. further,
The head unit 11 of the component transport frame 10 has a θ-axis motor 26 for rotating the component suction head 20 in the θ-axis direction.
When the θ-axis motor 26 is driven, the component suction head 20 rotates in the θ-axis direction via the timing belt 28.

The head 1 of the component carrying frame 10
1 is provided with a line sensor 40 as component recognition means for recognizing the component 60. The line sensor 40 emits a parallel light beam (for example, a laser beam) having a width wider than the length of the diagonal line of the component 60, and receives a small amount of the parallel light beam emitted from the light emitting unit 41 over the entire width. The light receiving unit 42 that can be detected at the element pitch is arranged to face each other at a required interval. The sensor surface 50 (FIG. 3) is formed by the parallel light flux.

As shown in FIG. 2, the head section 11 of the component transport frame 10 is provided with, for example, five component suction heads 20, four of which are arranged side by side along the X-axis direction. Has been established. The components 6 sucked by the suction nozzles 30 of these four component suction heads 20
0 is recognized by the light emitting unit 4
1 and the light receiving section 42 are arranged to face each other in the Y-axis direction.
On the other hand, the suction nozzle 30 of the other one component suction head 20
Line sensor 4 for recognizing component 60 sucked to
The 0 light emitting unit 41 and the light receiving unit 42 are arranged to face each other in the X-axis direction.

The automatic component mounting apparatus 100 has the moving mechanism as described above, and the component transport frame 10 is configured as described above. Therefore, depending on the driving of the X-axis motor 1 and the Y-axis motor 2, the component transport frame 10 The component suction head 20 and the line sensor 40
−Y plane, the suction head 30
The component 60 that has been sucked can be moved from the suction position to the mounting position. Also, depending on the driving of the Z-axis motor 21, the component suction head 20 moves up and down with respect to the line sensor 40, and the component 60 sucked by the suction head 30 can be moved to a position crossing the sensor surface 50. Furthermore, θ
Depending on the driving of the shaft motor 26, the component suction head 20
By rotating about the axis, the component 60 can be rotated in a horizontal direction at a position crossing the sensor surface 50.

The component suction heads 20 are provided by encoders incorporated in the X-axis motor 1 and the Y-axis motor 2, respectively.
The vertical position of the component suction head 20 is determined by the encoder 22 incorporated in the Z-axis motor 21, and the rotation angle of the component suction head 20 is determined by the encoder 27 incorporated in the θ-axis motor 26. Each is configured to be detected.

Further, the automatic component mounting apparatus 100 controls the driving of the X-axis motor 1, the Y-axis motor 2, the Z-axis motor 21 and the θ-axis motor 25,
A control unit (not shown) that calculates the position of the component 60 based on the detected value of 0 and corrects the movement data of the component suction head 20 based on the position of the component 60 and the acceleration of the component suction head 20 is provided. .

The automatic component mounting apparatus 100 is configured as described above. In order to accurately mount the component 60 at a specified position on the board from the component supply unit, a component suction / mount described below will be described. Perform the operation. Note that, for convenience, the component suction / mounting operation will be described by dividing it into a plurality of steps. That is, the component suction / mounting operation is performed by
The "sucking step" for picking up the components 60, the "moving step" for moving the component 60 from the suction position to the mounting position, and the "mounting step" for mounting the component 60 at the mounting position are performed in this order. In addition, during the moving process, the component 60 with respect to the suction nozzle 30 is recognized by the component recognition by the line sensor 40.
Based on the acceleration of the component suction head 20 at the time of component recognition by the line sensor 40 and the “N” of the suction nozzle 30 at the time of component recognition. The deviation amount from the steady state, that is, the “acceleration deviation amount calculation step” for calculating the acceleration deviation amount, and the movement data of the component suction head 20 necessary for moving the component to the mounting position are transferred to the suction deviation amount measurement step. A "movement data correction process" for correcting based on the suction displacement amount measured by the measurement and the acceleration displacement amount calculated in the acceleration displacement amount calculation process, and the corrected movement obtained in the movement data correction process. Component suction head 20 based on data
Is stopped at the end of the moving step, in which the component suction head 20 is stopped after moving the required amount. Hereinafter, each step will be described in detail.

<Sucking Step> First, to suck the component 60, the suction nozzle 30 is moved to a predetermined suction position where the component 60 is arranged. In this movement, the suction nozzle 30 is moved above the component 60 by driving the X-axis motor 1 and the Y-axis motor 2, and the suction unit 31 of the suction nozzle 30 is moved by driving the Z-axis motor 21. It is done by lowering it up close. When the suction nozzle 30 is moved to the suction position, the suction unit 31 suctions the vicinity of the center of the component 60 by the negative pressure.

<Movement Step> After the component 60 is sucked, the component 60 is moved toward a predetermined mounting position along with the suction nozzle 30. This movement is performed by driving the Z-axis motor 21, the X-axis motor 1, and the Y-axis motor 2.

The time change of the speed of the component suction head 20 in the X-axis direction during this movement is as shown in FIG. That is, assuming that the end of the movement is the timing T, the component suction head 20 is accelerated from the start of the movement to the timing T / 2 so that the speed becomes maximum at the timing T / 2, and thereafter, is decelerated until the end of the movement. You. The acceleration of the component suction head 20 in the X-axis direction at this time is as shown in FIG. That is,
The acceleration of the component suction head 20 is gradually increased until it reaches the maximum acceleration, and after being held at the maximum acceleration for a predetermined time, gradually decreases to zero at the timing T / 2. Thereafter, the component suction head 20 (at timing T /
2 to timing T), the acceleration from timing 0 to timing T / 2 and the acceleration (deceleration) in which the sign is reversed.

<Step of Measuring Attraction Displacement> In this movement process, the amount of attraction displacement in the X-axis direction and the Y-axis direction is measured in the following procedure (the position of the component 60 with respect to the reference position N is recognized). . First, the component 60 is moved to a height crossing the sensor surface 50 by driving the Z-axis motor 21. Next, while the component 60 is rotated around the Z axis by driving the θ-axis motor 25, measurement of a shadow generated by the component 60, that is, measurement of the laser measurement width W ((c) in FIG. 5) is started. Here, FIG. 5A shows the correspondence between the rotation angle of the component 60 and the laser measurement width W, and points P1, P2,
P3 and P4 are respectively (c), (d), and
3E and 3F are plots of the laser measurement width W and the rotation angle of the component 60. Thus, the sensor surface 50
When the component 60 is rotated with the position being set at the position, the size of the shadow changes according to the rotation angle. The measurement of the laser measurement width W is performed, for example, by first placing the component 60 at a predetermined angle (for example, 3
0 °), that is, from the state shown in FIG. 5 (c), until it is further rotated by a predetermined angle (for example, 150 °) in the direction B opposite to the direction A, ie, in FIG. 5 (f). Perform until the state.

In the process of rotation in the direction B, as shown in FIG. 5D, the component 60 becomes parallel to the
In some cases, the laser measurement width W of 0 becomes a minimum value. The laser measurement width W at this time is defined as a component width W1. In addition, the deviation amount in the laser measurement width W direction between the center N (reference position) of the suction nozzle 30 and the center P of the component 60 at this time is represented by ΔY.
And Here, the coordinates of the center N of the suction nozzle 30 in the laser measurement width W direction are stored in advance. The center P of the component 60 in the laser measurement width W direction can be obtained by calculating the average of the coordinates of both ends of the laser measurement width W.
Therefore, ΔY is obtained by calculating the difference between the coordinates of the center N and the center P in the laser measurement width W direction. Here, ΔY and the component 60 when the component width W1 is reached
(Replaced by the value of the encoder 27 of the θ-axis motor 26) is stored.

Further, if the component 60 is still rotated in the direction B after the laser measurement width W has once reached the minimum value, the laser measurement width W again has the minimum value as shown in FIG. There are times. The laser measurement width W at this time is defined as a component width W2. In addition, a deviation amount in the laser width W direction between the center N of the suction nozzle 30 and the center P of the component at this time is defined as ΔX. The calculation of ΔX is the same as the calculation of ΔY. Here, ΔX and the rotation angle β of the component 60 when the component width W2 is reached are stored.

The amount of adsorption deviation Δ
X and ΔY are respectively set in the X-axis direction and Y
It is used as a correction value for movement data in the axial direction. However, since the “coordinate of the center N of the suction nozzle 30” used in the calculation for obtaining ΔX and ΔY is a value assuming that no acceleration is applied to the component suction head 20, the movement data includes ΔX and ΔX. In addition to performing correction using ΔY and ΔY, it is necessary to perform correction due to acceleration as described below.

<Acceleration Deviation Amount Calculation Step> Since the component suction head 20 is not a completely rigid body, the component suction head 20 is bent (bent) when an acceleration is applied.
The suction nozzle 30 provided at the lower end of the component is shifted with respect to the head 11 of the component transfer frame 10. In contrast,
Since the line sensor 40 is incorporated in the head 11, the line sensor 40 moves integrally with the head 11 even when acceleration is applied, and does not shift with respect to the head 11. Therefore, due to bending, the suction nozzle 30 in the sensor surface 50
Is shifted from the steady state. This shift amount is assumed to be an acceleration shift amount. Even if the component 60 is recognized in the state where the acceleration shift amount is generated, if the acceleration shift amount is not corrected, the mounting position of the component 60 shifts by the amount of the acceleration shift amount. In order to avoid this, in the acceleration shift amount calculation step, the acceleration shift amount is obtained for use in later correction. Note that, in the present embodiment, for simplicity, 4
It is assumed that the acceleration deviation amount is obtained for only one component suction head 20. Since the acceleration deviation amount of these component suction heads 20 occurs only in the X-axis direction,
In the present embodiment, the acceleration deviation amount is obtained only in the X-axis direction.

For this purpose, first, when the laser measurement width W becomes the component width W1 and the component width W2 (timing T1 and timing T2 in FIG.
4, that is, the acceleration a and the acceleration b in FIG. 4B are obtained by calculation based on, for example, the moving distance and the moving time of the component suction head 20. here,
At the time of the maximum acceleration shown in FIG. 4B, the deviation amount of the center N of the suction nozzle 30 deviating from the steady state, that is, the maximum acceleration deviation amount is assumed to store a value checked in advance.
Then, by multiplying the ratio of the acceleration a and the acceleration b to the maximum acceleration by the maximum acceleration deviation amount, the acceleration deviation amounts at the time of the acceleration a and the acceleration b, that is, ΔY ′ and ΔX ′ are obtained.

<Moving Data Correction Step> Here, ΔX and ΔY, which are the suction displacement amounts obtained in the previous “adsorption displacement measurement step”, and the “acceleration displacement amount calculation step” are obtained. The movement data of the component suction head 20 is corrected by using the acceleration deviation amounts ΔX ′ and ΔY ′.
The mounting of the component 60 is performed, for example, as shown in FIG. 5B, in a state rotated by 180 degrees from the state of FIG. 5E. In the following description, for simplicity, the acceleration a and the acceleration b are both positive in the X-axis direction (measured while the component suction head 20 is accelerating in the X-axis direction). A description will be given of the case where the deviation from the center N of the nozzle 30 is in the state shown in FIG. 5 (in the mounted state, the nozzle center N is closer to the origin than the part center B in both the X-axis direction and the Y-axis direction). Do.

In this case, first, when measuring the suction deviation amount ΔY at the stage of FIG. 5D, the actual nozzle center N is closer to the origin in the X-axis direction than the stored nozzle center position. Has become. Therefore, the measured ΔY is larger than the originally required value, and the ΔY becomes the originally required value by subtracting ΔY ′. Similarly, FIG.
In the measurement of the suction deviation amount ΔX at the stage, the actual nozzle center N is closer to the origin in the X-axis direction than the stored position of the nozzle center. Therefore, the measured ΔX is also larger than the originally required value, and the ΔX becomes the originally required value by subtracting ΔX ′. Therefore, the movement data may be corrected so that the stop position of the component suction head 20 is on the origin side by ΔX−ΔX ′ in the X-axis direction, and is also on the origin side by ΔY−ΔY ′ in the Y-axis direction.

The correction of the movement data is performed in the state where the component 60 is mounted and either the nozzle center N or the component center B
The calculation formula differs depending on whether the position is on the origin side in each of the X-axis direction and the Y-axis direction. Further, acceleration a and acceleration b are
The calculation formula also differs depending on whether the value is measured during acceleration of the component suction head 20 or measured during deceleration. The movement data is, for example, data relating to the stop position of the component suction head 20, and is replaced by the values of the encoders of the X-axis motor 1 and the Y-axis motor 2. The above-described movement data correction step is performed before the movement of the component suction head 20 is stopped.

<Stop Step> In this stop step, the component suction head 20 is stopped based on the movement data corrected in the previous movement data correction step. That is, ΔX−ΔX ′ in the X-axis direction is compared with the case of the reference movement data.
The component suction head 20 is moved and then stopped so as to be on the origin side only by ΔY−ΔY ′ in the Y-axis direction. The rotation angle of the component 60 at the time of stopping is
The state is further rotated by 180 degrees than the rotation angle β, that is, the state is further rotated by 180 degrees from the state of FIG. As a result, the component 60 is very accurately placed at the mounting position.

<Mounting Step> After the component 60 is accurately moved to the mounting position, the negative pressure is released at this position and the component 60 is mounted. As a result, the component 60 is mounted very accurately at the mounting position.

According to the above embodiment, the movement data is corrected based on the acceleration of the component suction head 20 at the time of component recognition, and the required amount of the component suction head 20 is moved based on the corrected movement data. The component 60 is mounted.
Therefore, even if the component recognition is performed during acceleration / deceleration of the component suction head 20, the component 60 can be accurately mounted at the mounting position.

In the above-described embodiment, the case has been described where the component recognition means is moved integrally with the component suction head to perform recognition. However, the present invention is not limited to this. It may be of a fixed type, and recognition may be performed by fixed component recognition means. Although the case where a line sensor is used as the component recognition means has been described, the component recognition means may be a camera. Further, the acceleration of the component suction head at the time of component recognition may be obtained by measuring with an acceleration sensor.

[0033]

According to the present invention, not only the correction based on the position of the component with respect to the reference position recognized during the movement, but also the correction based on the acceleration of the component suction head at the time of component recognition is performed to obtain the movement data. Based on this movement data, the component suction head is moved by the required amount and the component is mounted, so that the component is accurately positioned at the mounting position due to the bending of the component suction head during acceleration / deceleration accompanying the movement. It is no longer necessary to move the component suction head based on the movement data that has deviated from the value required for mounting,
Even if the component recognition is performed during acceleration / deceleration of the component suction head, the component can be accurately mounted at the mounting position.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an automatic component mounting apparatus for performing an automatic component mounting method.

FIG. 2 is a schematic diagram for explaining an arrangement of a component suction head and a line sensor (component recognition means).

FIG. 3 is a side view for explaining the mechanism of the component suction head.

FIG. 4A is a diagram showing a time change of the moving speed of the component suction head, FIG. 4B is a diagram showing a time change of the acceleration of the component suction head, and FIG. 4C is a diagram showing a time change of the measurement width of the component. FIG. 6 is a diagram showing a correspondence relationship with the above.

FIG. 5 is a diagram for explaining how to recognize the position of a component with respect to a reference position.

[Explanation of symbols]

 Reference Signs List 20 component suction head 30 suction nozzle 40 line sensor (component recognition means) 60 component N center of suction nozzle (reference position) B center of component (position of component)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E313 AA02 AA11 CC03 CC04 DD02 DD03 DD13 EE02 EE03 EE24 EE35 EE37 EE50 FF24 FF26 FF28 FF33 FF40

Claims (3)

[Claims] A component is sucked at a suction position by a suction nozzle provided in the component suction head, the component is moved to a mounting position in accordance with the movement of the component suction head, and the component is released at the mounting position. In the automatic component mounting method to be mounted, in order to correct a component suction error and to mount the component at the mounting position with respect to the movement data of the component suction head necessary for mounting the component at the mounting position, In addition to recognizing the position of the component with respect to the reference position by component recognition means and performing a correction based on the recognized position of the component, the error of the recognized position caused by the acceleration applied to the component suction head for the movement is recognized. In order to correct and mount the component at the mounting position, a correction based on the acceleration of the component suction head at the time of component recognition is also performed, and the component suction head is moved based on the corrected movement data. An automatic component mounting method characterized by moving a required amount and mounting components. 2. The automatic component mounting method according to claim 1, wherein said recognition is performed by moving said component recognition means integrally with said component suction head. 3. The automatic component mounting method according to claim 1, wherein said recognition is performed by said fixed component recognition means.