JP3247925B2 - Electronic component mounting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounting method , and more particularly to an electronic component mounting method for controlling a mounting position of an electronic component by optically detecting a projection of the electronic component to be mounted. Things.

[0002]

2. Description of the Related Art Conventionally, when mounting a rectangular electronic component such as an IC on a circuit board in a mounting device such as a chip mounter, an image recognition process is performed on an image obtained using a CCD camera. 2. Description of the Related Art There is known a method of positioning a component in a non-contact manner.

In such an apparatus, a supplied component is sucked by a negative pressure by a suction nozzle as an electronic component holding means which is movable in a three-dimensional direction along the X, Y, and Z axes, and the component is sucked by a negative pressure. It must be accurately conveyed to a specified position on the substrate with respect to the center of the suction nozzle.

For this purpose, the inclination and the position of the component sucked by the suction nozzle with respect to the reference axis (X or Y axis) are accurately measured, and the inclination with respect to a specified direction and the positional deviation between the center of the suction nozzle and the center of the component are measured. Needs to be corrected.

FIG. 6 shows a configuration of an electronic component positioning device. In the drawing, reference numeral 5 denotes an electronic component to be positioned, and reference numeral 4 denotes a suction nozzle constituting a suction head of a chip mounter. In order to detect the rotation angle of the electronic component 5 sucked by the suction nozzle 4 and the suction position with respect to the suction nozzle 4, the light of the laser diode 1 is converted into parallel light by the collimator lens 2 to illuminate the electronic component 5. ing.

[0006] The parallel light flux 6 illuminates the electronic component 5, and the light that is not shielded by the electronic component 5 is received by the line sensor array 3.

If the width of the parallel light beam 6 by the laser beam and the effective detection length of the line sensor array 3 are larger than the length of the diagonal line of the electronic component 5, the suction nozzle 4 that has sucked the electronic component 5 is moved to the line sensor array as shown in the figure. The electronic component 5 is positioned at the center position CC of
Can be detected.

More specifically, when the width W of the shadow detected by the line sensor array 3 changes due to the rotation of the electronic component 5 and becomes parallel to the optical axis Lc of the parallel light beam 6 facing the electronic component 5, FIG. As shown in the figure, the width of the shadow W is minimized.

The width of the shadow W is, as shown in FIG. 6, the number of light receiving elements 3a constituting the line sensor array 3 whose light receiving output is equal to or lower than the threshold level Vs, that is, the bit whose binary output is 0. Obtained by counting the number.

That is, the rotation angle of the electronic component 5, that is, the rotation angle θ1 (FIG. 7) of the suction nozzle 4 up to the time when the width of the shadow W is minimized with respect to the optical axis Lc of the parallel light flux 6 or a direction orthogonal thereto. The center position of the shadow at this time, that is, the position of the center element of the light receiving elements 3a whose output of the line sensor array 3 is equal to or lower than the threshold level Vs is orthogonal to the optical axis of the electronic part 5 corresponding to the inclination angle of the electronic part 5. The direction can be detected as the center position in the direction of the movement.

[0011]

In the mechanism shown in FIG. 6, it is obvious that the size of the electronic component whose position can be detected is limited. Even if the distance between the laser light source unit 10 and the sensor unit 11 is made as large as possible, the effective detection width of the line sensor array 3 is finite, and the suction nozzle 4 is positioned at the center CC of the line sensor array 3 as described above. As long as the method of rotating the electronic component 5 is employed, the position of the electronic component 5 having a size exceeding the effective detection width of the line sensor array 3 cannot be detected.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an electronic component mounting method capable of accurately correcting a suction position of an electronic component to be mounted irrespective of the size of the electronic component and the detection unit. It is in.

[0013]

The present invention SUMMARY OF THE INVENTION The uses an electronic component holding means for holding the to electronic component to mounting, the light receiving means a projection of the electronic component held by the illuminated said electronic component holding means by the light emitting means In the electronic component mounting method of detecting the holding position of the electronic component by the electronic component holding unit by detecting the position of the electronic component, and correcting the holding position of the electronic component by the electronic component holding unit based on the detection result, The electronic component holding means is positioned at a first position with respect to a detection section comprising the light emitting means and the light receiving means, and a first partial projection of the electronic component is measured. The electronic component holding means is positioned at a second position with respect to the detection unit, and a second partial projection of the electronic component is measured, and the first partial projection is performed. 2 based on the partial projection, the amount of movement of the electronic component holding means between the first and second positions, and the positional relationship between the first and second positions and the detection unit. Along the center of the electronic component holding means and the electronic part based on the obtained width of the electronic component.
When correcting the displacement of the center of the product, the first and second positions are set according to the size of the electronic component. Also, the present invention provides the electronic component mounting method, wherein the electronic component holding means causes the detecting section comprising the light emitting means and the light receiving means to perform a first operation.
The electronic component holding means is positioned at a position, and a first partial projection of the electronic component is measured, and then the electronic component holding means is positioned at a second position with respect to the detection unit by the electronic component holding means. Is positioned to measure a second partial projection of the electronic component, the first partial projection, the second
Along the detection portion of the electronic component based on the partial projection of the electronic component, the amount of movement of the electronic component holding means between the first and second positions, and the positional relationship between the first and second positions and the detection portion. The width of the electronic component is determined based on the width of the obtained electronic component.
The misalignment between the center of the component holding means and the center of the electronic component
It is also characterized in that it is corrected (claim 2). further,
The present invention, in the electronic component mounting method , determines whether or not it is possible to measure the edge of the electronic component by positioning the electronic component holding means at a predetermined position of the light receiving means, if possible, at the predetermined position The projection of the electronic component is measured, and if not, the electronic component holding means is positioned at a first position with respect to the detecting section comprising the light emitting means and the light receiving means by the electronic component holding means, and the first of the electronic component is Measuring the partial projection of the electronic component and then measuring the second partial projection of the electronic component by positioning the electronic component holding means at the second position with respect to the detection unit by the electronic component holding means. ,
The first partial projection, the second partial projection, the movement amount of the electronic component holding means between the first and second positions, the first and second positions, and the position of the detection unit The width of the electronic component along the detection unit is determined based on the relationship, and the center of the electronic component holding unit is determined based on the obtained width of the electronic component.
In addition, the position of the center of the electronic component is corrected .

[0014]

According to the above structure, particularly the basic structure according to the second aspect, the electronic component holding means holds the electronic component at the first and second positions with respect to the detecting section comprising the light emitting means and the light receiving means. Positioning means, measuring first and second partial projections of the electronic component, and determining the first partial projection, the second partial projection, the first and second locations; The width of the electronic component along the detection unit is determined based on the amount of movement of the electronic component holding means during the interval, and the positional relationship between the first and second positions and the detection unit, and the width of the electronic component is determined based on the obtained width of the electronic component. Position control of the electronic component holding means at the time of component mounting , that is, the center of the electronic component holding means and the electronic
The displacement of the center of the component is corrected .

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows a configuration of a main part of an electronic component mounting apparatus employing the present invention. In FIG. 1, the suction nozzle 4 is driven by a suction unit 14 including a vacuum suction mechanism and the like, and the rotation angle about the Z axis is controlled by a θ motor 15. The motor 15 is controlled by the microcomputer 18 via the motor driver 17. Suction nozzle 4
The rotation angle around the Z axis is detected by the encoder 16 and fed back to the sensor control module 12 or the motor driver 17 and the microcomputer 18 described later.

At a predetermined position of the chip mounter, a measurement position for detecting the rotation angle of the electronic component sucked by the suction nozzle 4 is secured, and at this measurement position, the laser light source unit 10 and the sensor unit 11 are arranged to face each other. Is done. Laser light source unit 10 and sensor unit 11
Accommodates the laser diode 1, the collimator lens 2, and the line sensor array 3 shown in FIG.

The driving of the laser light source unit 10 and the light detection by the sensor unit 11 are performed by a sensor control module 12. The sensor control module 12
Drive of laser light source unit 10 and sensor unit 1
1 and a processing circuit for converting control data supplied from the microcomputer 18 so that the control circuit can handle the control data.

In this embodiment, the suction nozzle 4 is positioned at an intermediate position between the driving of the laser light source unit 10 and the sensor unit 11, and the suction position of the electronic component is determined by detecting the sucked electronic component. In the case where the size of the electronic component is larger than the detection length (width) of No. 3, the component sucked by the suction nozzle 4 is moved between the driving of the laser light source unit 10 and the sensor unit 11 in the X-axis direction in FIG. The width of the component is measured to determine the center position of the electronic component.

FIGS. 2 to 4 show this state. FIG.
Shows a control procedure of the microcomputer 18 at that time.

In this embodiment, three points A, B and C are defined on the center axis CC of the line sensor array 3 and the laser light source unit. The distances of these points A, B, and C from the ends (the right end in FIG. 2) of the line sensor array 3 are L1, L3, and L2, respectively. Here, L2 is L2 = Ws / 2
(Ws is the width of the line sensor array 3), and the point C is the center position of the line sensor array 3.

Further, points A and B are L2-L1 = L3-L2,
That is, it is set at the same distance from the point C, and is set to the position closest to the left and right effective detection pixels of the line sensor array 3 including an appropriate margin.

In such a configuration, in order to detect the suction position of the electronic component 5, in step S1 of FIG.
The suction nozzle 4 sucking the electronic component 5 is positioned at the point C, and in step S2, the suction nozzle 4 is rotated by the θ motor 15 by the line sensor array 3 to detect whether the left and right edges of the electronic component 5 can be detected. It is determined whether the suction position can be detected by the conventional method. If the suction position can be detected by the conventional method, the process of detecting the suction position of the electronic component 5 by the above-described conventional method is performed in step S3.

If the suction position cannot be detected by the conventional method, in step S4, as shown in FIG.
Is positioned at point A. In FIG. 3, for ease of explanation, the line sensor array 3 and one side of the electronic component 5 are parallel, but the electronic component 5 in the x-axis direction with respect to the suction nozzle 4 at a certain rotation angle θ of the suction nozzle 4. In order to obtain an offset (or further obtain an offset in the y-axis direction and center the suction position of the electronic component 5), the line sensor array 3 and one side of the electronic component 5 need always be parallel as illustrated. There is no.

In this state, the distance AL of the left edge 5A of the electronic component 5 from the right end of the line sensor array 3 in the figure is measured (step S5). From this distance AL,
Distance ADX from suction nozzle 4 at point A to edge 5A
Can be obtained as follows: ADX = AL-L1 (1)

Next, as shown in FIG. 4, the suction nozzle 4 is moved leftward in the figure (step S6), and is moved to the point B (the movement amount is (L3-L1)). Thereby, the distance BL of the right edge 5B of the electronic component 5 from the right end of the line sensor array 3 is measured (step S7).

Here, since the width Wx of the electronic component 5 in the x direction is Wx = L3 + ADX-BL (2), from the equation (1), Wx = (L3-L1) + AL-BL (( 3) That is, the width Wx of the electronic component 5 is obtained by adding the edge distance AL measured in steps S5 and S7 to the movement amount (L3-L1) from the point A to B, and subtracting BL.

Accordingly, the offset XF of the suction position of the electronic component 5 in the x-axis direction can be obtained from the equations (1) and (3) as follows: XF = ADX−Wx / 2 (4) (step S8) ).

Further, the electronic component 5 is rotated by 90 ° by the θ motor 15 (step S9), and in step S10, exactly the same processing as in steps S4 to S8 is performed to obtain the offset YF in the y-axis direction. (Step S10). If the offset XF in the x-axis direction and the offset YF in the y-axis direction are known, the suction position of the electronic component 5 can be corrected to the center position of the component (that is, within a two-dimensional plane) accordingly.

As described above, the line sensor array 3
The suction position of a component larger than the detection width can be corrected. The maximum detectable component width in the x- or y-axis direction is theoretically 2 (Ws-L1), and it is possible to measure a component that is almost twice the width of the line sensor array 3 (however, suction). If the suction position of the nozzle 4 is shifted from the center of the electronic component, the maximum detectable width is smaller than this. In addition, since it is usually necessary to measure components in both the x- and y-axis directions in the application of component mounting, the distance between the line sensor array 3 and the laser light source unit 10 limits the measurable component width. Become.

In the above description, the line sensor array 3 and one side of the electronic component 5 have been described as being parallel. However, at an appropriate point in the above-described processing (for example, the state shown in FIG. 3), the edge distance is minimized. By correcting the angle of the electronic component 5 so that it becomes smaller, it is possible to control the line sensor array 3 and one side of the electronic component 5 to be parallel, and to set the rotational position of the electronic component 5 to an arbitrary angle based on this position. Can be controlled.

In the above embodiment, the points A and B are located inside the line sensor array 3 in the width direction and at the same distance from the center point C of the line sensor array 3. It may be set to any known position. For example, by providing the point A or B outside the line sensor array 3, the width of the measurable component can be increased.

However, in this case, it is needless to say that the minimum width of the measurable component is limited (for example, when the suction nozzle 4 is moved to the point A or B, the component is added to the line sensor array 3). Shadows may disappear).

In view of this point, for example, the position of the point A or B is automatically set to an appropriate position according to the size of the part to be measured (for example, the edge of the part is detected by the line sensor array 3). It is also conceivable that the suction nozzle is moved to a position where it can be formed, and that point is set as point A or B), and the above-mentioned calculation is performed using the set point A or B.

[0035]

As is apparent from the above description, in the electronic component mounting method of the present invention, the electronic component holding means is positioned at the first position by the electronic component holding means with respect to the detecting section comprising the light emitting means and the light receiving means. Positioning and measuring a first partial projection of the electronic component, and then positioning the electronic component holding means at a second position with respect to the detection unit by electronic component holding means and positioning the electronic component at the second position. And measuring the first partial projection, the second partial projection, the movement amount of the electronic component holding means between the first and second positions, the first and second partial projections, A width of the electronic component along the detection unit is obtained based on a positional relationship between a second position and the detection unit, and the electronic component holding is performed based on the obtained width of the electronic component.
Since the basic configuration (claim 2) for correcting the displacement between the center of the means and the center of the electronic component is adopted, the size of the electronic component and the detection unit is not limited. Position control can be performed, and regardless of the size of the electronic component and the detection unit, the position of the electronic component to be mounted can be accurately controlled, and based on this, high-precision component mounting can be performed. The effect is obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a main part of an electronic component mounting apparatus employing the present invention.

FIG. 2 is an explanatory diagram showing a structure of a detection system of the electronic component mounting apparatus employing the present invention.

FIG. 3 is an explanatory diagram showing a component suction position detecting operation of the electronic component mounting apparatus employing the present invention.

FIG. 4 is an explanatory diagram showing a component suction position detecting operation of the electronic component mounting apparatus employing the present invention.

FIG. 5 is a flowchart showing a component suction position detection process in the electronic component mounting apparatus employing the present invention.

FIG. 6 is an explanatory diagram showing an outline of an angle or center detection processing mechanism of an electronic component.

FIG. 7 is an explanatory diagram illustrating a conventional angle or center detection process of an electronic component.

[Explanation of symbols]

 Reference Signs List 3 line sensor array 4 suction nozzle 5 electronic component 6 parallel light beam 10 laser light source unit 11 sensor unit 12 sensor control module 15 θ motor 16 encoder 17 motor driver 18 microcomputer

Claims (3)

(57) [Claims] [Claim 1] with an electronic component holding means for holding to the electronic component to mounting, by detecting the light receiving means a projection of the electronic component held by the illuminated said electronic component holding means by the light emitting means, the electron An electronic component mounting method for detecting a holding position of an electronic component of a component holding unit and correcting a holding position of the electronic component by the electronic component holding unit based on the detection result. The electronic component holding means is positioned at a first position with respect to the detecting section, and a first partial projection of the electronic component is measured.
The second partial projection of the electronic component is measured by positioning the electronic component holding means at the position, and the first partial projection, the second partial projection, the first and the second The width of the electronic component along the detection unit is obtained based on the amount of movement of the electronic component holding means between the positions 2 and the positional relationship between the first and second positions and the detection unit. Based on the width of the electronic component holding means
In correcting the displacement between the center and the center of the electronic component , the first and second positions are set according to the size of the electronic component.
An electronic component mounting method characterized by setting . 2. Using the electronic part holding means for holding to the electronic component to mounting, by detecting the light receiving means a projection of the electronic component held by the illuminated said electronic component holding means by the light emitting means, the electron An electronic component mounting method for detecting a holding position of an electronic component of a component holding unit and correcting a holding position of the electronic component by the electronic component holding unit based on the detection result. The electronic component holding means is positioned at a first position with respect to the detecting section, and a first partial projection of the electronic component is measured.
The second partial projection of the electronic component is measured by positioning the electronic component holding means at the position, and the first partial projection, the second partial projection, the first and the second The width of the electronic component along the detection unit is obtained based on the amount of movement of the electronic component holding means between the positions 2 and the positional relationship between the first and second positions and the detection unit. Based on the width of the electronic component holding means
A method for mounting an electronic component, comprising: correcting a displacement between a center and a center of the electronic component. 3. Using an electronic component holding means for holding the to electronic component to mounting, by detecting the light receiving means a projection of the electronic component held by the illuminated said electronic component holding means by the light emitting means, the electron An electronic component mounting method for detecting a holding position of an electronic component of a component holding unit and correcting a holding position of the electronic component by the electronic component holding unit based on the detection result, wherein the electronic component holding unit is located at a predetermined position of the light receiving unit. To determine whether the measurement of the edge of the electronic component is possible, if possible, measure the projection of the electronic component at the predetermined position,
If not, the electronic component holding means positions the electronic component holding means at a first position with respect to the detection section comprising the light emitting means and the light receiving means, and the first of the electronic components
Is measured by the electronic component holding means, and then the second projection is performed on the detection unit.
The second partial projection of the electronic component is measured by positioning the electronic component holding means at the position, and the first partial projection, the second partial projection, the first and the second The width of the electronic component along the detection unit is obtained based on the amount of movement of the electronic component holding means between the positions 2 and the positional relationship between the first and second positions and the detection unit. Based on the width of the electronic component holding means
A method for mounting an electronic component, comprising: correcting a displacement between a center and a center of the electronic component.