JPH08155796A - Hole boring method using x-ray and its method - Google Patents

Abstract

PURPOSE: To correctly obtain the drilling position of a printed circuit board in the drilling using the X-ray. CONSTITUTION: A printed circuit board is irradiated with the X-ray from an X-ray irradiating means, the transmitted image of the identification mark provided on the printed circuit board is photographed (72) by an X-ray camera, and this result is image processed to detect the center position of the mark (73). A drilling means is moved (74) so as to be opposite to this mark center position to achieve the drilling (75). Then, the identification and the hole are simultaneously photographed (76) and both positions are compared with each other (77). If both positions are deviated from each other, the corrective data are prepared based thereon. The images M, H of the identification mark and the hole are simultaneously photographed after the drilling, and the results are used as the corrective data. Because the deviation attributable to the movement of the work in the drilling operation is eliminated, drilling can be made at the correct position in the subsequent drilling operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for picking up an X-ray transmission image and making a hole on the basis of position data obtained by image processing of the picked-up result, and an X-ray hole making apparatus therefor.

[0002]

2. Description of the Related Art When drilling a printed circuit board,
An identification mark for positioning is provided in advance, an image of the identification mark is picked up by the image pickup means, the center position is obtained by performing image processing on this, and this position is punched by the punching means.
In a multilayer substrate or the like, when the identification mark at the punching position is not exposed on the surface, the ordinary visible light camera cannot capture the identification mark. Therefore, an X-ray irradiating means and an X-ray camera are adopted to detect the position of the work identification mark by recognizing the X-ray transmission image. The X-ray drilling device is a device that performs drilling by using the above-mentioned means with reference to the identification mark provided on the multilayer substrate.

Positioning for drilling with an X-ray drilling device is performed by irradiating a work placed on a table with X-rays, adjusting the gain of the X-ray camera, and adjusting the voltage of the X-rays.
It is monitored by adjusting the current. As described above, the transmission image of the identification mark by the X-ray is image-processed by the image processing device, and the drilling means such as a drill is moved to the position determined by the image processing using the XY table, and the hole is drilled at that position. ing.

As one example of such a method, Japanese Patent Laid-Open No.
Japanese Patent No. 152048 discloses "a method for automatically drilling reference mark positions on a multilayer printed circuit board". This is to image the mark twice. Once the mark center position is detected, move the X-ray camera so that the center position and the center of the screen of the X-ray camera face each other, and then image the mark again. Then, the mark center position is re-determined by image processing. As a result, the imaging accuracy of the camera is improved and the accuracy of punching is improved.

According to the above method, although it is possible to surely improve the accuracy to some extent, an error due to factors other than the camera is still included and it is not perfect.

Therefore, a method is conceivable in which the position of the hole actually drilled is confirmed to find the actual error. That is,
After drilling, the X-ray is irradiated again to capture an image of the hole and image processing is performed to calculate the center position. Then, this is compared with the center position of the identification mark obtained by imaging before drilling, and the correction data is created based on the deviation between the two.

[0007]

In the above conventional example, the positional coordinates of the identification mark and the hole are compared on the assumption that the identification mark detected before drilling and the identification mark after drilling are at the same position. Is being done. However, in reality, the workpiece is often slightly moved due to drilling and misalignment, so even if the position coordinates of the identification mark before drilling and the hole after drilling are compared, the correct position There was a problem that the deviation could not be detected.

Therefore, an object of the present invention is to accurately capture an identification mark and a drilled hole after drilling using X-rays at the same time, calculate the amount of deviation from the position coordinates of both, and obtain correction data. The purpose is to enable drilling into positions.

[0009]

In order to achieve the above object, the method of punching using X-rays according to the present invention is an image picked up by picking up an image of an identification mark on a raw printed circuit board by an image pick-up means. Image processing to detect the center position of the identification mark, align the drilling means with the center position of the identification mark, and after drilling the printed board by the drilling means, the identification mark and the The holes that have been drilled are imaged at the same time, the images obtained by simultaneously imaging after drilling are subjected to image processing to obtain the position data of the identification mark and the position data of the holes, and compare them to create correction data. In the subsequent drilling, the drilling means is positioned after the center position of the identification mark is adjusted to the correction position based on the correction data.

An X-ray punching device for performing the above method is a punching means for punching a printed circuit board, an X-ray irradiation means for irradiating the printed circuit board with X-rays, and an identification mark provided on the printed circuit board. Image pickup device for simultaneously picking up the transmission image of the image and the punched hole, an XY table mechanism for moving the punching device and the image pickup device relative to the printed circuit board, and an image processing device for processing the image obtained by the image pickup device. And a central processing unit for controlling the image pickup unit and the hole forming unit based on the data input from the image processing unit, and the central processing unit stores the position data of the identification mark and the hole that are simultaneously imaged after the hole formation. An arithmetic circuit for comparing and calculating the deviation amount and a storage circuit for storing the deviation amount calculated by the arithmetic circuit are connected.

[0011]

[Operation] Since the correction data is created by comparing the position data of the hole after drilling with the data obtained by simultaneously capturing the identification mark that is the reference for drilling, the error based on the accuracy of the camera is created. A value that corrects all mechanical errors of the drilling means is required. Further, by connecting a memory circuit to the central processing unit, this correction data can be stored and used for the correction of the positional deviation in the subsequent drilling work.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 2 and 3 show the entire structure of the present embodiment, in which an image pickup means 2 for forming a transmission image of a work produced by irradiation of X-rays and a drilling means 3 are arranged below the table 1. There is. A printed circuit board 4, which is a work, is placed on the upper surface of the table 1 in a transportable manner.

A support member 5 is provided above the table 1 at a predetermined interval, and an X-ray irradiation means 6 is supported on the support member 5. A protective cover 7 is fixed to the lower surface of the support member 5. Inside the protective cover 7, there are provided X-ray passages and X-ray leakage prevention means (not shown) for preventing leakage of X-rays.

Below the X-ray irradiating means 6, a protective tube 8 forming a passage 8a for X-rays emitted from the protection tube 8 is connected. A shutter 9 is provided in the protective tube 8 so as to traverse the X-ray passage 8a, and the shutter 9 is driven forward and backward by a shutter cylinder 10 to open and close the passage 8a. A vertical guide groove 8b is formed on the outer periphery of the protective tube 8.

Below the protective tube 8, a protective cylinder 11 having an X-ray passage 11a communicating with the passage 8a is provided so as to be able to come into contact with and separate from the work 4. This protective cylinder 11 is used for the work 4
It also serves as a clamper for pressing on the table 1, and is fixed to the lower end of the cylindrical body 12 fitted to the outer periphery of the protective tube 8. A plate 13 having a guide 13a slidable in the guide groove 8b on its inner surface is integrally provided on a part of the cylindrical body 12. Below the support member 5, a cylinder 14 is provided as a means for lowering the protective cylinder 11 in parallel with the cylindrical body 12. The cylinder 14 transmits the extension of the cylinder rod 14 a to the cylinder 12 via the connecting member 15 fixed to the cylinder 12 to lower the protective cylinder 11. The protection cylinder 11 is provided with a braking means (not shown) and can be stopped at any position via the control means. The protection cylinder 11 is raised by the cylinder 14, and is locked by the return spring 16 to the connecting member 15 so that the protection cylinder 11 does not drop by its own weight when the air is down.

On both sides of the protective tube 8, sensor support plates 17,
17 is suspended and sensors 18, 18 are provided inside the lower end of each sensor support plate 17. Sensor 1
Reference numeral 8 detects whether or not the printed circuit board 4 is located below the X-ray passages 8a and 11a, and the shutter 9 is opened and closed by the output of the detection signal of this sensor.

Although not shown, a shielding member as an X-ray leakage preventing means is provided around the X-ray passages 8a and 11a provided below the X-ray irradiating means 6. As the shielding member, the same lead-containing synthetic resin sheet as in the prior art is used, and two sheets having vertical cuts at appropriate intervals are provided in parallel at the hem portion. When the printed circuit board is irradiated with X-rays, the inside of the shielding member is hermetically sealed so that the hem portion of the shielding member hits the work on the table so that the X-rays do not leak to the surroundings.

A work receiver 21 having a built-in sensor is located between the table 1 and the substrate 4 in the vicinity of a position where an operation such as imaging and drilling is to be performed. The work receiver 21 is provided with a mirror that reflects the light from the sensor 18, and the presence or absence of the substrate can be detected by blocking the light from the printed circuit board 4.

Next, XY for moving the image pickup means 2 and the punching means 3 located below the table 1 to the working position.
The table mechanism (moving means) 22 will be described. Below the table 1, a support plate 23 is fixedly attached to a main body (not shown), and a pair of rails 24 and 25 parallel to the X direction are provided on the upper surface of the indicator plate.

FIG. 4 shows the state of the upper surface side of the indicator plate 23. On the indicator plate 23, the rails 24 and 2 described above are provided.
5 are provided, and sliders 26a, 26b, 26c, 26d slidable in the X direction are provided on these rails, respectively.
Is attached. Further, sliders 27a, 27b, 27c and 27d, which are guided in the vertical (Y) direction of the drawing, are fixed to the upper surfaces of these sliders with their surfaces fitted to the rails facing upward. This slider 2
6a to 26d and the other sliders 27a to 27d are arranged in a direction substantially orthogonal to each other.

On the sliders 26a to 27d, Y
A pair of rails 28 and 29 extending in the direction are fitted. A motor 30 is mounted on the support plate 23, and a lead screw 31 connected to the drive shaft of the motor is rotatably provided. Then, the nut 32 is screwed into the lead screw 31, and the nut 3
2 is a slider 26a and 2 through the nut holder 33.
It is fixed to 7a. Therefore, when the lead screw 31 is rotated by driving the motor 30, the nut 32, the nut holder 33, and the sliders 26a and 27a move in the X direction. At this time, the sliders 26b to 26d and 27b to 27d connected to the rail 28 also move integrally.

As shown in FIGS. 4 to 6, rails 28 and 29 are provided.
A movable table 34 is fixedly attached to the top. A motor 35 is fixed on the moving table 34, and a lead screw 36 is rotatably connected to a drive shaft of the motor. A nut 37 is screwed onto the lead screw 36, and this nut is fixed to a nut holder 38. This nut holder 38 corresponds to the slider 2 described above.
It is fixed to 6b and 27b and is not fixed to the moving table 34.

In this structure, when the lead screw 36 is rotated by the driving of the motor 35, the nut 37 is turned to Y
Although the nut holder 38 is fixed to the sliders 26b and 27b, and the slider 26b is fitted to the rail 25, the nut holder 38 cannot move in the Y direction although it tends to move in the Y direction. Therefore, even if the lead screw 36 rotates due to the driving of the motor 35, the nut 37 does not move, and the motor 3
5 and the moving table 34 move in the Y direction. Since the XY mechanism 22 is configured as described above, the moving table 34
Is movable in the XY directions by driving the motors 30 and 35.

Next, the image pickup means 2 and the punching means 3 will be described. A support plate 39 is erected on the moving table 34, and the X-ray camera 2 serving as an imaging means is held on the support plate via a connecting plate 40 and a tubular member 41.
The X-ray camera 2 is connected to an image processing device, a central processing device, and the like, which will be described later, and the operation of the XY table mechanism 22 and the like described above is performed based on the result of image processing of the transmission image of the identification mark on the printed circuit board 4. Controlled. In this embodiment, a vidicon camera is used as the X-ray camera 2, which is relatively inexpensive and is less likely to cause halation when simultaneously capturing images of holes and marks, as will be described later.

A pair of vertical rails 42 and 43 are attached to the opposite surface of the support plate 39 (see FIGS. 5 and 7). A rail guide (not shown) is provided on the holding frame 44 that holds the perforating means 3, and the rail guide is slidably fitted to the rails 42 and 43.

As shown in FIG. 3, the drilling means 3 is composed of a spindle motor 3a, a collet chuck 3b fixed to the upper end of the spindle motor 3a, and a drilling member such as a drill 3c held by the collet chuck. . The drilling means 3 is for drilling the printed circuit board 4 by rotating the drill 3c by driving the spindle motor 3a. A chip cover 45 for discharging chips is attached to the upper end of the punching means 3.

Next, with reference to FIG. 7, a drive mechanism for driving the punching means 3 in the vertical direction (Z direction) will be described.
It should be noted that FIG. 7 shows B- of FIG. 5 in order to make the configuration easy to understand.
The cross section is taken along line B.

As shown in the figure, a lead screw 48 extending in the Z direction is rotatably attached to the support plate 39 via an attachment member 47. A nut 49 is screwed onto the lead screw 48, and the nut is attached to the holding frame 44 via a nut holder 50.
It is stuck to. The upper end of the lead screw 48 is connected to the belt wheel 51. The mounting member 47 holds a motor 52 for raising and lowering the punching means, and the drive shaft of the motor 52 is connected to the belt wheel 53. Therefore, when the belt wheel 53 rotates by driving the motor 52, the rotation is transmitted to the belt wheel 51 via the belt 54, and the lead screw 48 rotates accordingly. Then, the nut holder 50 is integrated with the nut 49,
The punching means 3 held by the holding frame 44 is moved up and down.

Next, the control means of the X-ray drilling device in this embodiment will be described with reference to the block diagram shown in FIG. Central to the control means is the central processing unit (CP
U) 61, which is connected to the central processing unit so as to organically operate the punching means 3 and the XY table mechanism 22 in response to the output signal thereof. The X-ray irradiating means 6 is also controlled by the central processing unit 61, and the irradiated X-rays are transmitted through the work, and the transmitted image of the mark attached to the work and the perforated hole are X-rayed. The line camera 2 is provided so that it can be imaged. X-ray camera 2
An image processing apparatus 62 is connected to the central processing unit 61 so that the processed data can be output. In the central processing unit 61, the arithmetic circuit 63 for calculating the deviation of the coordinate position between the two data and the memory circuit 64 for storing the data of the position coordinate of the identification mark, the position coordinate of the drilling position, etc. Connected interchangeably. An output device 65 such as a display is connected to the central processing unit 61 so that the coordinate position and the like can be constantly monitored. The output device 65 can be equipped with a recording means such as a printer as required.

Next, an explanation will be given of how to make a hole at a predetermined position on the printed circuit board according to the present invention with reference to the flow chart shown in FIG. Prior to the drilling work, the printed circuit board 4 as a work is set on the table 1 (7
1). Therefore, the position of the identification mark attached to the unprocessed printed circuit board is detected by image recognition to determine the drilling position. First, the moving table 34 is moved by driving the motors 30 and 35 of the XY table mechanism 22, and the X-ray camera 2
Through the hole 1a of the table 1 and the printed circuit board 4,
The X-ray irradiator 6 is moved to a work position facing the X-ray passages 8a and 11a. Next, the cylinder 1 for raising and lowering the protective cylinder
The cylinder rod 14a of No. 4 is extended, and the protection cylinder 11 is lowered (see FIGS. 2 and 3).

Here, the sensor 18 causes the printed circuit board 4 to
When the shutter 9 is opened by driving the shutter cylinder 10 after confirming the presence of the X-rays, the X-ray passages 8a and 11a communicate with the X-ray outlet of the protective tube 8 (see FIG. 3). X-rays can pass through the printed circuit board 4. The transmission image of the identification mark provided on the printed circuit board 4 is captured by the X-ray camera 2 provided below the table 1 and sent to the image processing device 62 (see FIG. 1).

Next, while observing the monitor 65, while adjusting the position of the printed circuit board 4 by image recognition, the position of the identification mark is adjusted so as to be within the frame showing the measurement area provided in the central portion of the monitor, and the foot is adjusted. Press a switch (not shown). As a result, the cylinder 14 is driven, the cylinder rod 14 a thereof is extended, and the protective cylinder 11 is lowered via the connecting member 15. The lower end of the protective cylinder 15 is brought into contact with the upper surface of the printed circuit board 4, and is pressed against the upper surface of the table 1 to be held at the aligned position.

Here, a transmission image of the identification mark is picked up by the X-ray camera 2 (72). The captured image of the identification mark is output to the image processing device 62 and subjected to image processing.
The obtained image data is output to the central processing unit 61, and the arithmetic circuit 63 calculates the center position of the mark (7).
3). When the center position of the identification mark is calculated, the motors 30 and 35 of the XY table mechanism 22 are driven by the instruction from the central processing unit 61 to move the punching means 3 in the X direction and the Y direction.
In the direction (74), the tip of the drill 3c of the drilling means is aligned with the center of the drilling mark.

Next, the motor 52 for raising and lowering the punching means 3 is started, and the drill 49 is rotated by the screw 49 via the holding frame 44 by the drilling spindle motor 3a to punch the printed circuit board 4. (7
5). The chips generated by punching are discharged from the chip cover 45 (see FIG. 3). After drilling, cylinder 1
4 is driven to retract the protective cylinder 11 and return to the original position.

When the drilling operation is completed, the identification mark and the drilled hole are simultaneously imaged by the X-ray camera 2 (76). As shown in FIG. 9, the field of view (X
The transmission image M of the identification mark and the image H of the opened hole are projected on the image capturing area 65a of the line camera. Here, the description will be made assuming that the center coordinates of both images M and H are slightly deviated from each other and are located at M1 and H1, respectively.
Both images picked up here are sent to the image processing device 62, where they are subjected to image processing, and the image signals are output to the central processing device 61. In addition, in the present embodiment, in order to distinguish three types of images of the inside of the hole, the mark printing portion, and the background portion of the substrate, so-called ternarization is performed instead of normal binarization. The three shades of color are distinguished.

Both images M and H of the identification mark and the opened hole
The image data of
Then, the positions of the central coordinates M1 and H1 are compared (77). As a result, the values of the x-coordinate shift amount (x1-x2) and the y-coordinate shift amount (y1-y2) are calculated, and the correction data is created (78). This correction data is stored in the storage circuit 64 and is used as data in the drilling work from the next time. Therefore, the positioning for drilling in the subsequent drilling work is corrected by the numerical value calculated from the position of the identification mark and the center coordinate of the drilled hole which are imaged at the same time after drilling. The accuracy of is improved.

As described above, the work of simultaneously imaging the hole and the identification mark to create the correction data may be performed only once when the hole making machine is manufactured, and then repeated when the user makes a hole. There is no need to do it. Of course, the above-mentioned work may be performed and the correction data may be updated for each drilling.

In this embodiment, a kind of drilling machine for making holes by rotating a drill is used as the drilling means, but the drilling means is not limited to this, and punching means or other drilling means may be used. Further, the work is not limited to the printed circuit board, but is applicable to general plate materials that can transmit X-rays.

[0039]

According to the present invention, when drilling is performed using X-rays, the identification mark and the drilled hole are simultaneously imaged after drilling, and the positional deviation of the center coordinates of the two is made from the obtained image data. By calculating, even if the printed circuit board may move during drilling, it is possible to accurately calculate the amount of deviation without being affected by it. The accuracy of the dawn improves. Further, since this deviation amount is stored as correction data and the correction data can be used for the subsequent drilling work, it is possible to always drill at an accurate position.

Therefore, according to the present invention, the accurate positioning of the holes is extremely facilitated, so that the efficiency of the work of boring the printed circuit board is improved.

[Brief description of drawings]

FIG. 1 is a block diagram of an X-ray drilling device according to the present invention.

FIG. 2 is a right side sectional view showing a main part of the configuration of the present invention.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a plan view showing the configuration below a moving table of an XY table mechanism.

FIG. 5 is a plan view of an XY table mechanism.

FIG. 6 is a left side view of the XY table mechanism.

7 is a sectional view taken along line BB of FIG.

FIG. 8 is a flowchart of a drilling method according to the present invention.

FIG. 9 is a plan view of an imaging screen.

[Explanation of symbols]

 2 Imaging means (X-ray camera) 3 Drilling means 4 Printed circuit board (work) 6 X-ray irradiation means 22 XY table mechanism 61 Central processing unit 62 Image processing device 63 Calculation circuit 64 Storage circuit M Transmission image of identification mark H of hole image

Claims (2)

[Claims] 1. An image pickup means picks up an image of an identification mark of a raw printed circuit board, the imaged image is image-processed to detect a center position of the identification mark, and a punching means is used for a center position of the identification mark. Position, and the printed board is perforated by the perforation means, the identification mark and the perforated hole are simultaneously imaged by the imaging means, and the image obtained by simultaneously imaging after the perforation is imaged. The position data of the identification mark and the position data of the hole are obtained by processing, and the correction data is created by comparing the position data of the identification mark with the position data of the hole. A hole using X-rays, wherein the center position of the identification mark is aligned with the correction position based on the correction data by the hole forming means, and then the hole is formed. Only way. 2. A perforation means for perforating a printed circuit board, an X-ray irradiation means for irradiating the printed circuit board with X-rays, a transmission image of an identification mark provided on the printed circuit board, and the perforated hole. Imaging means for simultaneously imaging
An XY table mechanism for moving the perforating means and the image pickup means relative to the printed circuit board, an image processing device for processing an image obtained by the image pickup means, and data input from the image processing device. And a central processing unit for controlling the image pickup unit and the hole forming unit based on the central processing unit. The central processing unit compares the position data of the identification mark and the hole imaged at the same time after the hole is formed, and the deviation amount thereof. An X-ray punching device, characterized in that an arithmetic circuit for calculating the above is connected to a memory circuit for storing the amount of deviation.