JPH02134900A - Device for inserting multipin component - Google Patents

Abstract

PURPOSE:To cause the breakage of pins due to an inserting failure to be nipped in the bud and improve the safety of an inserting process by performing optimum positioning with respect to all of the terminal pins while coping with deviation of the through hole positions on a board. CONSTITUTION:When electronic components 1 are located just above the positions in which the electronic components 1 are inserted, a light projecting part 14 and a photodetector 13 of a measuring apparatus are set to each height in such a way that laser light is applied to pointed ends 2 of terminal pins and the measurement of the size of overlapping images as well as their center positions of the lined terminal pins is performed. A printed board 7 in which through holes 8 for inserting components 1 are provided is fixed to a moving stage 17 and positioning is performing by making the stage 17 move in two directions X and Y by means of two drive motors and guide mechanisms 15 and 16. A camera 31 is installed just above the moving stage 17 and all of the through holes on the board come into the field of vision of this camera and then their expanded images are taken in a monitor device. A personal computer 18 calculates the correction for alignment between the components and the board on the basis of measurement data of the terminal pins by means of a laser measuring apparatus 19 as well as measurement results of the hole positions by means of counting two directions X and Y.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for inserting a pin grid array type electronic component having a large number of terminal pins into a printed circuit board.

[Conventional technology]

In the field of electronic component mounting, there is a tendency for the number of terminals for connecting X-element components to boards to increase because it is advantageous for achieving higher density. In particular, a component called a pin grid array type has several hundred to several thousand terminal pins 2 on the back side, as shown in Figure 9, and these terminal pins are inserted all at once into through holes provided on the board. The structure is connected by soldering.

The terminal pins 2 are arranged regularly at a constant pitch to form a grid-like arrangement, and the through-holes on the board side into which they are inserted are also arranged in a similar manner corresponding to the pins.

When inserting such a multi-pin component into a board, highly accurate positioning is required so that all the pins can be inserted into the corresponding through holes, and manual insertion is difficult. In addition, when inserting with a machine, there may be dimensional errors in the outer circumferential surface of the part gripped by the chuck, variations in the position of the terminal pins relative to the part outline, and deviations in board hole positions, etc., due to the design dimensions of the board and parts. In-place inserts based on may fail. Furthermore, since these components are generally expensive, damage to the terminal pins due to insertion failure must be avoided, and highly reliable insertion is required.

Among the above-mentioned dimensional variations in parts and boards, there is a high possibility that terminal pins in particular will be deformed during the manufacturing process of the parts or during the subsequent no-no-linking process. If the deviation is used as the amount of correction during alignment, the accuracy of insertion will be greatly improved.

Figure 10 shows a conventional example using this method (Japanese Patent Application Laid-open No. 6-1-
56000). Among the many terminal pins 2 on the lower surface of the component 1, the diagonally located terminal pin 3 is used as a reference pin, and a light guide 4 illuminates this pin, and the reflected light is reflected from the terminal pins, two of which are provided on the same surface. The part 1 is detected by the first sensor 5 and the second sensor 6, and the part 1 is corrected to the correct position. Sensors 5, 6
Since the amount of light received is maximum when the reference pin 3 is on each optical axis, if the sensors 5 and 6 are installed in the predetermined positions in advance, the output of each sensor will be maximized by slightly moving the parts. Move parts forward, backward, left and right by searching for their position.

It can be positioned in the rotational direction. As mentioned above, this method of realizing positioning using pins instead of the external shape of the component is a simple and good method that deals with the misalignment of the pin position, which is the biggest obstacle when positioning the component. Conventional technology performs alignment based on two specific terminal pins, so if the positions of these two pins deviate from their original positions, even if the majority of other pins are in the correct position. However, as a result, there was a problem in that it was difficult to achieve optimal positioning depending on the position of the reference pin.

Considering the fact that among the terminal pins arranged in a lattice pattern, those located on the outer periphery or in the four corners are easily deformed, it is necessary to perform alignment by referring to a large number of pin positions, including those inside the lattice arrangement. . In addition, although terminal pins are not easily deformed, it is difficult to maintain high positional accuracy with through-holes on the board, especially when holes corresponding to one component are required to maintain a predetermined positional relationship. However, it is often seen that deviations from the reference position at the time of design occur due to expansion and contraction of the entire board. Therefore, it is necessary to measure the position of the virtual lattice formed by the through-holes in the substrate at the time of insertion, and to correct the deviation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pin grid array type component insertion device that can optimally align all terminal pins while dealing with deviations in the positions of through holes on a board.

[Means for solving the lW set]

The above purpose is to provide an insertion head mechanism that has a chuck that rotates in a horizontal plane while gripping a component and can be stopped in any direction, and a side view of the terminal pins arranged in a row on the component gripped by the chuck. A means for capturing images of overlapping pins and measuring their thickness and center position for each row at once, a table mechanism that can place a printed circuit board on it and move it in two directions at right angles to position it, and a table mechanism that can position the printed circuit board on the table. A means for capturing the through hole with a camera and measuring its position, and a calculating means for calculating the amount of correction from the reference position necessary for alignment of both from the position measurement results of the terminal pin and the through hole by each of the above measuring means. This is achieved by having a configuration with the following features.

[Effect]

To measure the terminal pin position, grasp the component and perform it in the following state.
Since the grip is not changed until the insertion is complete, errors in external dimensions of the parts do not affect alignment. Also, when looking at the terminal pins lined up in a row from the side, you can capture the images of the overlapping pins and check their thickness and center. By measuring the position of each row at once, the position information of all terminal pins can be revealed in a short time. In other words, by slightly rotating the component using the rotation mechanism of the insertion head and minimizing the width of the rows of pins, the orientation of the rows of pins becomes clear, and then by rotating the component by 90'', the width of the rows of pins is minimized. By determining the center position of each pin row, the position of the pin row in the gripped state becomes clear.

To measure the position of the through-holes on a board, place the printed circuit board, move it in two directions at right angles, use a table mechanism that allows positioning, and use a camera to capture each representative hole of the through-holes arranged in a grid pattern until the center of the screen is measured. The displacement of the through-hole position is determined by detecting the amount of table movement at that time.As mentioned above, although the holes corresponding to one component satisfy a predetermined positional relationship, the deviation of the through-hole position from the reference position of the entire board Since the error is caused by misalignment, it is sufficient to measure a small number of representative holes using this method.

Finally, based on the position measurement results of the terminal pins and through holes, correction amounts in the X, Y, and six directions from the reference position are calculated using a calculation means. Then, based on this correction amount, the table on which the board is placed is X.

By gripping the component in the Y direction and moving the nine insertion head mechanisms in the θ direction, the desired alignment can be achieved.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 8.

As shown in the first factor, an electronic component 1 having a large number of terminal pins 2 is gripped by a chuck 9, and the chuck 9 is attached to an insertion head 10, rotated in a horizontal plane (by a motor 11), and rotated in an arbitrary It can be stopped in any direction. The insertion head 10 can be inserted up and down by a drive motor and a guide mechanism 12 (not shown) and can be stopped at any position.

The light emitting part 14 and the light receiving part 13 of the measuring machine using a laser are i
When child part 1 is directly above the insertion position.

It is set at a height such that the tip of the terminal pin 2 is irradiated with a laser beam, and it is possible to measure the thickness and center position of the overlapping image of the terminal pins arranged in a row, which will be described in detail later. .

A printed circuit board 7 provided with a through hole 8 into which the component 1 is inserted is fixed to a moving stage 17 by means not shown, and the moving stage 17 is moved by two drive motors (not shown) and a guide mechanism 15, 16. Y
Can move in two directions for positioning.

The camera 31 is mounted directly above the moving stage 17, and can take in all the through holes 8 of the printed circuit board 7 into its field of view, and displays an enlarged image thereof on a monitor device (not shown).

Next, the configuration of the control section of this embodiment will be explained with reference to FIG. Personal computer (hereinafter referred to as a personal computer) 18
is connected to the laser measuring machine part 19, and takes in data related to the measurement of terminal pins. Also,
The personal computer 18 gives movement commands to the following motors via the sequencer 20 to cause each mechanism to perform a predetermined operation. 2
1 and 22 are motor drivers for the moving stage 17; 23;
゜24 indicates a motor for each of the X and Y axes, and the moving stage 17
The amount of movement in each direction is calculated by counters 25 and 26 and calculated by α]
and is fed back to the personal computer 18. 28.27
30 and 29 respectively indicate the θ-axis rotation motor and its driver of the insertion head 10, and 30 and 29 respectively indicate the two-axis motor and its driver for the insertion operation that moves the insertion head 10 up and down.The images captured by the camera 51 are shown on the monitor. A portion 33 surrounded by a zero-dot line projected on the device 32 represents the worker, and the worker 33 moves the joystick 6 until the through-hole image projected on the monitor device 32 is located at the center of the screen.
4 to adjust the position of the printed circuit board 7 on the moving stage 17. Then, when the through-hole image matches the center of the screen, press the hole data import button 55,
The moving stage position at that time is imported into the personal computer 18.

The personal computer 18 calculates a correction amount for aligning the component and the board based on the terminal pin measurement data by the laser measuring device 19 and the hole position measurement results by the counters 25 and 26 in the X and Y directions.

The personal computer 18 also issues a series of operation commands for insertion according to an algorithm to be described later.

FIG. 6 is a flowchart showing the process of inserting one electronic component using this apparatus. Starting with the electronic component gripped by the insertion head, we first measure the terminal pins.
Next, among the board through-holes into which the terminal pins are inserted, the four corner holes are representatively measured. There is no problem even if the terminal pin measurement and board hole measurement are performed in parallel.If a bent pin is detected in the terminal pin measurement, insertion is stopped to prevent damage to the pin. Next, calculate the positioning correction amounts ΔX, ΔY, Δ based on the measurement results of the terminal pins and board holes.
θ is calculated, and based on this, a movement command is given to the motor of each axis. Finally, the electronic component is inserted into the board to complete the insertion of one electronic component.

By repeating this process nine times, a plurality of electronic components are inserted.

Next, with reference to FIG. 3, the principle of laser measurement performed in this embodiment to measure terminal pins will be explained. Reference numeral 36 represents a laser scanning source irradiated from the measuring machine light projector 14. The laser spot source, which originally has a minute diameter, is converted into a scanning source by a rotating mirror inside the measuring machine, and is further converted into a scanning source in parallel with the lens. As a result, the width in the scanning direction can be made approximately equal to the length of the terminal pin array of the electronic component.

The width of the laser scanning beam is smaller than the length of the terminal pin arrangement, −
If it is not possible to measure all rows at once, it is necessary to move the parts and perform the measurement in several batches. Regarding the rotating mirror, lens, etc. inside the measuring machine described above, if the terminal pins 2 arranged in a row (not shown in the figure) are placed so that their tips are exposed to the laser scanning light, the laser beam will be emitted. is blocked by the pin, creating a shadow. Then, the laser light intermittent by the pin array is again focused on one point by the measuring device light receiving section 13, and its intensity is detected. At this time, by measuring the time that the bright or dark areas last, the dimensions a, b shown in the figure,
It becomes possible to measure o.

FIG. 4 is a schematic diagram showing a state in which the terminal pin 2 on the electronic component 1 is irradiated with laser scanning light from the top of the figure.

The laser measuring machine measures the dimensions B of the shaded portion shown in the figure, ~85, and the dimensions t, ~t6 of the gap portion.

The dimension S of the shaded part, ~85, is the width of the pin row, and if the center position of the pin row is at the center of the width of the row, it can be found by combining it with the dimension t, ~t6 of the gap part. .

If each pin row includes a pin that is significantly bent, the measured width of the pin row increases in accordance with the amount of deformation.

Therefore, the measured width of each row is 8.0, using the measured width of the row of pins when a pin that cannot be inserted is included as a criterion. ~B5
It is possible to determine whether insertion is possible by comparing the size with . If it is determined that there is a terminal pin that cannot be inserted, the insertion is stopped, thereby further increasing the safety against insertion failure.

If the pin rows are not aligned parallel to the laser scanning light, the width of the pin rows is increased or decreased by rotating the electronic component 1 by a minute amount using the rotation mechanism of the insertion rod 10. By utilizing this fact to find the orientation of the component where the width of each pin row is the minimum, it is possible to make the virtual grating formed by the pin tips parallel to the direction of the laser beam. If the component is placed in this state during alignment with the board, which will be described later, rotation correction caused by the terminal pin can be omitted.

After the measurement in one direction is completed, the component is rotated in the right angle direction by the rotation mechanism of the insertion head 10 and a similar measurement is made to determine the position of the terminal pin in both the X and Y directions. Although it is desirable to obtain data regarding all rows when measuring in each direction, it is also possible to measure the rows by dividing them depending on the case. The calculation of the results of these measurements, the calculation of the measurement results, the rotation of the insertion head, etc. are automatically performed by the personal computer 18.

Figure 5 shows how to calculate the deviation from the reference position of the virtual grid formed by the pins from the measurement results of the terminal pin positions obtained in this way. Assuming that the amount of deviation from the desired position is d, ~d5, the amount of deviation of the virtual grid to be sought is calculated as dx by averaging this amount. The amount of deviation dy is calculated in the same way in the Y direction.

Next, the positional relationship between the hole position and the electronic component at the time of camera measurement will be explained with reference to FIG. H1 to H4 indicate four corner holes as representative holes, and the coordinates thereof are obtained by measurement with the camera 31. C, e C2 is the camera 31 and the insertion head 10
This indicates the distance between the centers of rotation of the device, which needs to be measured once during the device adjustment stage. - Once measured, it can be used as a constant. dx, d)' is the result of position measurement of the nine terminal pins described above. This is the amount of deviation from the reference position of the grid formed by the pins. S is the dimension of the target position of the four corner pins, and this is the dimension for generating the position of the target virtual four corner pins P, ~P4 to bring the substrate holes H5 to H4 closer together in the correction amount calculation using the least squares method described below. It is.

Using this S, P and ~P4 are calculated as follows.

p, = knee < C4l C2) + (dx I a)'
) + (-8,5)P2 ”(C1+C2)+(d
x+d7)+(S+S)p,=(C,+02)+(
ax, ay)+(s,-5)P4=CG,,C2)+(
dX, d7) + (SIS) Figure 8 is a diagram showing the concept of the correction movement amount calculation method using the least squares method.
The th pin is Pl, the corresponding 1st hole is Hl, and the respective X+y coordinates are Pit l pt21 h
Let it be il l h12. The board is corrected by ΔX and ΔY1 components are moved by Δθ so that the sum of squares for all combinations of distances between corresponding pins and holes is minimized. The amounts of movement ΔX, ΔY, and Δθ can be calculated by simply giving the position coordinates of the pin and hole, so the calculation formula is shown below.

ΔX knee (■ΔθΣP1.--ΔθΣP□2-Σh1.
)...(11ΔY=-(-ΔθΣPi1-μsΔθΣ
P12-Σh1□) (2) Δθ in the ftl, tz1 formula is calculated by substituting the result of the formula (3).

By performing alignment correction using this least squares method, it is possible to find optimal positions for all the pins and holes targeted for calculation. In this embodiment, the components and the board are aligned by applying this calculation to the terminal pin/array position information based on the measurement results of all columns and the coordinates of the four holes based on the four-corner measurements.

〔Effect of the invention〕

As explained in detail above, according to the present invention, it is possible to optimally align all the terminal pins while dealing with the misalignment of the through-hole positions on the board, so it is possible to prevent damage to the pins due to insertion failure. Furthermore, the safety of the insertion process is increased, which has the effect of improving the reliability of circuit connections.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the control section of the embodiment, FIG. 5 is a diagram showing the principle of measuring terminal pins using a laser, and FIG. 4 is a diagram showing terminal pins using a laser. Fig. 5 is a top view showing the pin measurement state, Fig. 5 is a top view showing the method for determining the pin position, Fig. 6 is a flowchart showing the insertion process, and Fig. 7 is a schematic showing the positional relationship between the pin and hole during alignment. Figure 8 is a perspective view showing the correction amount calculation method, Figure 9 (
a). (b) is a side view and bottom view showing the target product, and FIG. 10 is a schematic diagram showing the prior art. 1...Electronic component, 2...Terminal pin 7...Printed circuit board, 8...Through hole 9...Chuck, 10...
... Insertion head 12 ... Lifting guide, 13.14 ... Laser measuring machine 17 ... Moving stage 18 ... Personal computer 19 ... ...Laser measuring machine control unit 20...Sequence 25.24.Old..Motor for moving stage 25.26.
... Counter 51 ... Camera 32 ... Monitor device 33 ... Operator. e Figure 9

Claims (1)

[Claims] 1. In a device that inserts terminal pins of pin grid array type components into through holes provided on a printed circuit board,
An insertion head mechanism has a chuck that rotates in a horizontal plane while gripping a component and can be stopped in any direction, and terminal pins arranged in a row on the component gripped by the chuck are arranged in a row, and when viewed from the side, pins overlap each other. A means for capturing an image and measuring its thickness and center position for each row at once, a table mechanism that can place a printed circuit board and move it in two directions at right angles to position it, and a through hole in the printed circuit board on the table. It is equipped with a means for capturing the position with a camera and measuring its position, and a calculation means for calculating the amount of correction from the reference position necessary for alignment of both terminal pins and through holes from the position measurement results of the terminal pins and through holes by each of the above measuring means. A device for inserting multi-pin components.