JPH06252598A - Measuring method for inclination and position of component attracted by attraction nozzle - Google Patents

Abstract

PURPOSE:To measure inclination and a two-dimensional of a square component attracted by an attraction nozzle accurately by rotating it just once by the attraction nozzle inside parallel luminous flux. CONSTITUTION:A square component 5 is attracted by an attraction nozzle 4 tilted offset to a fixed direction to a standard axis. The component 5 is positioned inside parallel luminous flux 6 whose width is larger than a length of a diagonal thereof, and the attraction nozzle 4 is rotated continuously to an opposite direction of the fixed direction while a width of shadow generated by the parallel luminous flux 6 which is screened by the component 5 is measured. For measurement, a rotation angle of the attraction nozzle 4 whereon a first minimum width of the shadow is attained is regarded as an inclination angle to a standard axis of the component 5. A central position of a width of the shadow at that time is regarded as a central position of the component 5 in a standard axial direction and a central position of a width whereat a second minimum width of shadow is attained is regarded as a central position of the component 5 in a direction at right angles to the standard axis to measure each thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction nozzle in an automatic component mounting apparatus for automatically mounting electronic components such as ICs, chip resistors or capacitors designated at predetermined positions on a printed circuit board. The present invention relates to a method for measuring the inclination and position of a component that is adsorbed on a substrate.

[0002]

2. Description of the Related Art Such an automatic component mounting apparatus is equipped with X,
Equipped with a suction nozzle that can move in the three-dimensional directions along the Y and Z axes, sucks the supplied component by negative pressure with the suction nozzle, and mounts the component programmed based on the center of the suction nozzle. Depending on the operation, it is accurately transported to the specified position on the substrate and mounted.

Therefore, the inclination and position of the component sucked by the suction nozzle with respect to the reference axis (X-axis or Y-axis) are accurately measured, and the inclination with respect to the specified direction and the positional deviation between the center of the suction nozzle and the center of the component. Need to be corrected. The chip component used in such an automatic component mounting apparatus is generally a square component such as an IC having a square or rectangular planar shape.

Therefore, as a method of measuring the inclination and position of the component sucked by the suction nozzle, as shown in the principle diagram of FIG. 7, the laser light emitted by the laser diode 1 is passed through the collimator lens 2 to form a parallel light beam. 6, the parallel light beam 6 is received by the CCD line sensor array 3 which is arranged to face the collimator lens 2 at a distance, and the component 5 sucked by the suction nozzle 4 is positioned in the parallel light beam 6. There is a method in which the suction nozzle 4 is rotated as shown by the arrow and the width of the shadow thereof is measured.

The width of the parallel light beam 6 by this laser beam and the effective detection length of the CCD line sensor array 3 are determined by the component 5
If the length is larger than the length of the diagonal line, the width W of the shadow detected by the CCD line sensor array 3 changes due to the rotation of the component 5, and the two opposing sides of the component 5 are the optical axes L of the parallel light flux.
When it becomes parallel to c, the width W of the shadow becomes minimum as shown in FIG. As shown in FIG. 7, the width W of this shadow is equal to the number of light-receiving elements 3a constituting the CCD line sensor array 3 whose light-receiving output is below the threshold level Vs, that is, the binarized light-receiving output is "0". It is obtained by counting the number of bits of ".

Therefore, the rotation angle of the component 5 up to the time when the width of the shadow becomes minimum, that is, the rotation angle θ1 (FIG. 8) of the suction nozzle 4 is the component with respect to the optical axis Lc of the parallel light beam 6 or the direction orthogonal thereto. 5, the center position of the shadow at this time, that is, the light receiving output of the CCD line sensor array 3 is below the threshold level Vs.
The position of the central element of a (the number of the element when the number of light-receiving elements is 256) corresponds to the central position of the component 5 in the direction orthogonal to the optical axis, so that they can be easily and accurately measured. be able to.

[0007]

However, in order to know the center position of the component, the one-dimensional center positions along the X axis and the Y axis for moving the suction nozzle in two dimensions are required. Therefore, conventionally, it is necessary to measure the shadow width while rotating the component sucked by the suction nozzle in the parallel light flux as described above, and obtain the center position of the shadow width when it becomes a minimum. , Twice in the X-axis direction and in the Y-axis direction. Therefore, the relationship between the rotation speed of the suction nozzle and the time is as shown by the solid line in FIG. 9, and there is a problem that the measurement takes time.

The present invention has been made in view of the above points, and shortens the measurement time when measuring the inclination and position of a component sucked by a suction nozzle using the parallel light flux as described above. With the goal.

[0009]

In order to achieve the above-mentioned object, the method for measuring the inclination and position of a component sucked by a suction nozzle according to the present invention has a rectangular component offset tilted in a certain direction with respect to a reference axis. In this state, the suction nozzle is sucked, the component is positioned within a parallel light flux having a width wider than the diagonal length of the component, and the suction nozzle is measured while measuring the width of a shadow caused by the parallel light flux being blocked by the component. Continuously rotating in a direction opposite to the fixed direction, the rotation angle of the suction nozzle when the width of the shadow first reaches a minimum value is measured as the tilt angle of the component with respect to the reference axis line, and at that time, The center position of the width of the shadow is the center position of the part in the reference axis direction, and the center position of the width when the width of the shadow reaches the minimum value in the second direction is a direction orthogonal to the reference axis line of the part. Heart of Each is measured as a location.

Alternatively, a square part is sucked by a suction nozzle in a state where one side thereof is substantially parallel to the reference axis, and the suction nozzle is rotated in one direction by a predetermined angle larger than the estimated suction error angle of the part, The component is positioned in a parallel light beam having a width wider than the length of the diagonal line, and the suction nozzle is continuously operated in the direction opposite to the one direction while measuring the width of a shadow caused by the parallel light beam being blocked by the component. And the tilt angle of the component with respect to the reference axis line, the center position in the reference axis direction, and the center position in the direction orthogonal to the reference axis line are respectively measured in the same manner as described above. Good.

In that case, at the time of measurement, it is desirable that the angle at which the suction nozzle is rotated in the direction opposite to the one direction is slightly larger than the sum of the rotation angle in the one direction and 90 °.

[0012]

According to the present invention, by rotating the component sucked by the suction nozzle only once in the parallel light flux by the suction nozzle, the inclination and the two-dimensional position of the component can be accurately measured. The relationship between the rotation speed and the time at that time is shown by the broken line in FIG. 9, and the required time is shortened as shown by t1 to t2 in the conventional case. Also, if the components are offset and tilted in a certain direction with respect to the reference axis and then sucked by the suction nozzle to perform measurement, it is not necessary to rotate in the opposite direction before starting measurement, and the minimum rotation is required. You can make measurements at.

However, even if the component is not always attracted in a state in which it is tilted in a fixed direction, if the component is attracted in a state in which one side of the component is substantially parallel to the reference axis, the suction nozzle of the estimated component is attracted. The measurement may be performed by rotating in one direction by a predetermined angle larger than the error angle and then rotating in the opposite direction. In that case, it is necessary to rotate it in one direction in advance at a slight angle (about 5 °), and at the time of measurement, it is sufficient to rotate it by an angle (about 100 °) slightly larger than the rotation angle in that direction + 90 °. The measurement can be performed efficiently.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 2 is a perspective view showing an example of an apparatus for carrying out the method for measuring the inclination and position of the component sucked by the suction nozzle according to the present invention.

This apparatus comprises a laser light source unit 10 and a sensor unit 1 which are arranged in parallel and face each other with a required space.
1, a sensor control module 12 that controls these, a suction unit 14 including a suction nozzle 4, a θ motor 15 that rotates the suction unit 14, an encoder 16 that generates a pulse according to the rotation angle, and a motor that drives the θ motor 15 A driver 17, a microcomputer 18 that controls the entire apparatus, and various cables 20 to 24 that connect them.
And its connector and the like. 25 is a power cable.

This device is actually incorporated in an automatic component mounting device, and the microcomputer 18 includes control of a three-dimensional moving mechanism (not shown) along the X, Y, and Z axes of the suction portion 14. Can also control

The laser light source unit 10 contains the laser diode 1 and the collimator lens 2 shown in FIG. 7, and emits a parallel light flux having a width wider than the length of the diagonal line of the component to be measured by the laser light. To do. The CCD line sensor array 3 shown in FIG. 7 is also provided in the sensor unit 11, and the parallel light flux emitted from the laser light source unit 10 can be detected by the small light receiving element pitches arranged in a row over the entire width.

The sensor control module 12 drives a circuit for causing the laser diode in the laser light source unit 10 to emit light with a constant intensity and a CCD line sensor array in the sensor unit 11 to sequentially read the light reception output of each light receiving element. , A binarization circuit for comparing it with a predetermined threshold level and converting it into a binary signal indicating light and dark, correlating the rotation angle and the shadow width measurement value by counting the angle pulse from the encoder 16 under measurement. It is equipped with a memory for storing the data.

Operation from component suction to mounting by this device (controlled by the microcomputer 18)
Will be described with reference to the flowchart of FIG. 1 and FIGS. 3 to 5.

When this process is started, first, the component (for example, IC) supplied in step 1 is sucked by the suction nozzle 4 and moved to the measurement position. That is, the negative pressure supplied to the suction unit 14 of FIG. 2 causes the suction nozzle 4 to suck the vicinity of the center of the rectangular component 5 and, as shown in FIGS. 3 and 4, between the laser light source unit 10 and the sensor unit 11. Parallel luminous flux 6
It is located at a predetermined height inside. However, at this time, it is not necessary to emit the parallel light flux 6 from the laser light source unit 10.

The movement of the suction portion 14 during this time is performed in X, Y, Z
By a moving mechanism (not shown) in the axial direction. Further, at this time, the component 5 is adsorbed in a state in which a predetermined side is substantially parallel to the laser light source unit 10 and the sensor unit 11 with the X axis (which is orthogonal to the optical axis Lc of the parallel light flux 6) as a reference axis. To do so. At this time, the center of the suction nozzle 4 is at a predetermined position on the optical axis Lc of the parallel light flux 6, the optical axis Lc is parallel to the Y axis, and passes through the central position C of the CCD linear sensor array 3 shown in FIG. Has become.

Then, in step 2, the suction nozzle 4 is rotated by 5 ° in the CCW direction (direction indicated by an arrow A in FIG. 3) together with the sucked component 5. This is the rotation required to make sure that the parallel point (the point where the shadow width is minimal) can be found immediately when the expected suction error angle of the suction nozzle 4 is ± 2.5 °. is there.

Then, in step 3, a measurement start command is sent to the sensor control module (hereinafter abbreviated as "SCM") 12. As a result, the SCM 12 causes the laser light source unit 10 to emit the parallel light beam 6 and brings the sensor unit 11 into a measurable state.

Then, the θ motor 1 is applied to the motor driver 17.
5 is driven to rotate the suction nozzle 4 together with the component 5 by the θ motor 15 in the CW direction (the direction of arrow B in FIG. 3) by 100 °. In the meantime, the relationship between the rotation angle due to the counting of the angle pulse generated by the encoder 16 and the width of the shadow of the component 5 measured based on the light receiving output of each light receiving element from the sensor unit 11 is shown in FIG. , SCM
Store in 12.

When the rotation is completed, in step 5, SCM1
Rotation angle θx when the width W of the shadow shown in FIG. 2 to FIG. 5 first reaches the minimum value Wx, the center position X0 of the shadow at that time, and rotation angle θy when it reaches the second minimum value Wy and the time Read the center position Y0 of the shadow of. This θx is X of component 5
The inclination with respect to the axial direction, θy −90 °, is the inclination in the Y-axis direction, and since both should originally be equal, it is possible to read only θx, but to improve the measurement accuracy, both are read, In the next step 6, the tilt angle Δθ is
It is calculated by the calculation of Δθ = (θx + θy−90 °) / 2.

Then, in step 7, the motor driver 17
Reversely rotate the θ motor 15 to move the suction nozzle 4 to the component 5
Together with CCW direction (direction A in FIG. 3) (100 ° −
By rotating by Δθ), the inclination of the component 5 is corrected and each side thereof is made parallel to the X axis or the Y axis.

After that, the suction unit 14 is three-dimensionally moved with respect to the X, Y, and Z axes by a moving mechanism (not shown) to mount the component 5 on the target position on the board. The X and Y values of the movement data at that time are set. With respect to, the deviation of the center position X0 of the component 5 in the X-axis direction from the center position C of the suction nozzle 4 X0-C
And the deviation Y0-C from the center position C of the suction nozzle 4 at the center position Y0 in the Y-axis direction is used as a correction value.

By doing so, the necessary components can be obtained by continuously rotating the suction nozzle 4 in the CW direction by an angle slightly larger than the angle + 90 ° previously rotated in the CCW direction (100 ° in the above example). It is possible to measure the inclination and the center positions in the X-axis direction and the Y-axis direction.

Further, by rotating the component about twice the suction error angle estimated in the opposite direction to the rotation direction at the time of measurement, the component suctioned by the suction nozzle is in the above error angle range with respect to the reference axis. In any direction, the parallel point (the point where the width of the shadow becomes the minimum) is detected immediately by the rotation of the part after the measurement is started, so the rotation angle during measurement is minimized. be able to.

However, when the component is sucked by the suction nozzle, if it can be set so that it is always offset and inclined in a certain direction with respect to the reference axis, the rotation before the start of measurement in step 2 in the flowchart of FIG. It is not necessary to perform the measurement, and when the measurement starts, the estimated maximum offset tilt angle +9
The suction nozzle 4 may be rotated by an angle slightly larger than 0 °. By doing so, the measurement efficiency can be further improved.

FIG. 6 is a perspective view showing a specific example of the rotating and raising / lowering mechanism of the suction portion. The parts corresponding to those shown in FIG. 2 are designated by the same reference numerals. In FIG. 2, the suction unit 14, the θ motor 15, and the encoder 16 are coaxially directly connected to each other for simplification of description, but in the mechanism shown in FIG. 6, they are arranged on different axes.

In FIG. 6, reference numeral 30 denotes an arm that is two-dimensionally moved by an XY moving mechanism (not shown), and has a frame 31 fixed thereto. Horizontal part 31 of this frame 31
A pipe 33 is provided through which the hose 32 is fitted and penetrates through a, and the upper end of the pipe 33 is attached to the vertical portion 3 of the frame 31.
A slider which can be raised and lowered along a guide rail 34 fixed to 1b is held, a suction portion 14 having a suction nozzle 4 is provided at a lower end portion, and a pulley 36 is fixedly provided at an intermediate portion.
The hose 32 communicates with the suction nozzle 4, and a negative pressure for sucking the component 5 is supplied from the outside.

Further, the θ motor 15 and the encoder 16 are integrally attached to a bracket 37 fixed to the frame 31, and a belt 38 is stretched between the rotary shaft and the pulley 36. Then, the pipe 33 is rotated by the θ motor 15 via the belt 36 and the pulley 36, whereby the suction nozzle 4 of the suction portion 14 is rotated together with the component 5 attracted thereto as shown by the arrow D. it can.

A rack 39 is provided on the side surface of the slider 35.
And a pinion 40 that meshes with the rack 39 is vertically fixed to the frame 31.
It is fixed to the common shaft 43 of the Z-axis motor 41 and the encoder 42 attached to 0. Then, the Z-axis motor 41
When the pinion is rotated by the rack 39, the rack 39 and the slider 35 integrated with the rack 39 move up or down, whereby the suction unit 14 moves up and down together with the pipe 33 in the Z-axis direction. Further, the entire mechanism is provided with an X (not shown) via the arm 30.
-The Y moving mechanism moves in the X-axis direction and the Y-axis direction.

[0035]

As described above, according to the present invention, the rectangular component sucked by the suction nozzle is rotated only once by the suction nozzle in the parallel light flux.
The inclination and the two-dimensional position of the component can be accurately measured, and the time required for the measurement can be shortened. Therefore, if this is applied to an automatic component mounting apparatus, the component mounting efficiency can be greatly improved.

[Brief description of drawings]

FIG. 1 is an operation from component suction to mounting by the device shown in FIG. 2 (controlled by a microcomputer 18).
It is a flowchart of.

FIG. 2 is a perspective view showing an example of an apparatus for carrying out a method for measuring the inclination and position of a component sucked by a suction nozzle according to the present invention.

FIG. 3 is a plan view of the same main portion.

FIG. 4 is a front view of the same main portion.

5 is a diagram showing an example of the relationship between the rotation angle and the shadow width stored in the SCM 12 in step 4 of FIG.

FIG. 6 is a perspective view showing a specific example of a rotation and lifting mechanism of a suction unit 14 in FIG.

FIG. 7 is a principle diagram of a method for measuring the inclination and position of a component sucked by a suction nozzle, which is a target of the present invention.

FIG. 8 is a diagram showing the relationship between the rotation angle of the component and the width of the shadow during the measurement.

FIG. 9 is a diagram showing the relationship between the change in the rotational speed of the component and time during the measurement, comparing the conventional method with the method according to the present invention.

[Explanation of symbols]

1: Laser diode 2: Collimator lens
3: CCD line sensor array 3a: Light receiving element
4: Suction nozzle 5: Rectangular component (IC) 6: Parallel light flux 10: Laser light source unit 11:
Sensor unit 12: Sensor control module 14: Adsorption part 1
5: θ motor 15 16: encoder 17: motor driver 18:
Microcomputer

Claims (3)

[Claims] 1. A rectangular component is attracted by a suction nozzle in a state in which it is offset and inclined in a certain direction with respect to a reference axis, and the component is positioned within a parallel light flux having a width wider than the length of its diagonal line. While continuously measuring the width of the shadow caused by being blocked by the component, the suction nozzle is continuously rotated in the direction opposite to the fixed direction, and the suction when the shadow width first reaches a minimum value. The rotation angle of the nozzle is measured as an inclination angle with respect to the reference axis line of the component,
The center position of the width of the shadow at that time is set to the center position of the part in the reference axis direction, and the center position of the width when the width of the shadow reaches the minimum value for the second time is set to the reference axis of the part. A method for measuring the inclination and position of a component sucked by a suction nozzle, characterized by measuring the center position in each of the orthogonal directions. 2. A rectangular component is attracted to a suction nozzle with one side thereof substantially parallel to a reference axis, and the suction nozzle is rotated in one direction by a predetermined angle larger than an estimated suction error angle of the component, The component is positioned in a parallel light beam having a width wider than the length of the diagonal line, and the suction nozzle is continuously operated in the direction opposite to the one direction while measuring the width of a shadow caused by the parallel light beam being blocked by the component. Rotation, the rotation angle of the suction nozzle in the direction when the width of the shadow first reaches a minimum value is measured as an inclination angle of the component with respect to the reference axis line, and the width of the shadow at that time is measured. The center position is the center position of the part in the reference axis direction, and the center position of the width when the width of the shadow reaches the minimum value for the second time is the center position of the part in the direction orthogonal to the reference axis line. Measure each A method for measuring the inclination and position of a component sucked by a suction nozzle. 3. The angle at which the suction nozzle is rotated in the opposite direction to the one direction at the time of measurement is set to an angle slightly larger than the sum of the rotation angle in the one direction and 90 °. A method for measuring the inclination and position of a component sucked by the suction nozzle described.