KR20040030312A - Vision Inspection Apparatus using a Full Reflection Mirror - Google Patents

Abstract

PURPOSE: A vision inspection unit using a total reflection mirror and an inspecting method thereof are provided to minimize the driving torque and the vibration by rotating an X-Y-axis total reflection mirror of a photographing position control module to change a photographing position. CONSTITUTION: A vision inspection unit using a total reflection mirror includes a substrate position control module(2), an independent lighting unit(3), a photographing position control module(4), a camera(6), a control unit(7), and a vision processing unit(8). The substrate position control module(2) is used for fixing a PCB including components on a predetermined position. The independent lighting unit(3) is installed on the substrate position control module. The independent lighting unit includes a first lamp to illuminate the PCB. The photographing position control module(4) is installed on the independent lighting unit. The photographing position control module is used for changing a reflection angle to a desired position on the PCB by adhering a total reflection mirror at a shaft of an X-Y-axis rotary motor. The camera(6) is used for photographing an image of the PCB reflected by the photographing position control module. The control unit(7) includes a motion controller for controlling the photographing position control module and the substrate position control module, a lighting controller for controlling an operation of the independent lighting unit, and an image processor for controlling an operation of the camera and converting the received image of the camera to digital data. The vision processing unit(8) reads the photographed image and decides a state of the photographed image.

Description

Vision Inspection Apparatus using a Full Reflection Mirror

The present invention relates to a vision inspection apparatus and a vision inspection method using a total reflection mirror.

In general, Surface Mounting Technology (SMT) for assembling surface-mount components on a printed circuit board (PCB) or the like is a technique for miniaturizing and integrating surface-mounting devices (SMD) and the surface-mounting components. Development of precision assembly equipment for precise assembly and technology for operating various assembly equipment.

Here, the surface mount line is composed of equipment such as a surface mounter and a vision inspection device, and the surface mounter is a device for mounting surface mount parts on a printed circuit board. The surface mount parts include various surface mount parts supplied in the form of tape, stick, and tray. It is supplied from the feeder, transferred to the mounting position on the printed circuit board, and then placed on the fixed position on the printed circuit board. The vision inspection apparatus checks whether the component is in good condition or not after completing the soldering process. In addition, the printed circuit board is transferred to the next process according to the inspection result through the vision inspection device.

In this case, in the conventional vision inspection method using a vision inspection device, when the printed circuit board is soldered through the conveyor, the position adjusting device adjusts the initial position. By taking a picture of the soldering part of the soldering machine, the condition of the soldering part is output to the monitor and calculated by the vision device to check the good and bad of the component mounting.

However, the conventional vision inspection apparatus and its method are to fix the camera and move the printed circuit board, or to fix the printed circuit board and to move the camera to photograph the presence and the soldering parts of the various parts on the printed circuit board to be inspected As the method is applied, the load is large when driving each component, and the vibration is severe. Therefore, when the mounting state of the component is inspected before soldering, the position of the component is deviated by the vibration of the inspection apparatus itself. In addition, the camera or the printed circuit board must be secured to move the space, so the device itself is enlarged to occupy a large installation space. In addition, conventionally, the distance between the camera and the object to be inspected has a problem in that the inspection position cannot be visually checked during the inspection.

On the other hand, Patent Registration No. 340012 known through the Republic of Korea Patent Publication has been proposed "product inspection method and computer vision system using a movable mirror".

1 is an overall configuration diagram for explaining the pre-registered invention, Figure 2 is a configuration diagram showing the operating state of the pre-registered invention.

Referring to FIG. 1, an X-Y axis movable mirror 400, 500, a half mirror 600, and a light source 700 are installed between the inspection area 300 and the camera 200 by a high speed motor. Accordingly, the image is taken for the entire area by moving the movable mirrors 400 and 500 at high speed while taking an image of the small areas in the inspection area 300 to perform the inspection. Such a vision system 100 of the present invention can minimize the occurrence of noise and impact by eliminating the mechanical mechanism by changing the optical path by using a movable mirror to increase the inspection speed by extremely small mechanical moving parts.

However, the foregoing pre-registered invention has the following problems.

First, since the distance between the inspection area 300 and the light source 700 is far, the amount of light reaching the light source 700 from the inspection area 300 and the amount of light reaching the camera 200 in the inspection area 300 are lost. It becomes larger in proportion to the square of the distance between the inspection area 300 and the light source 700. That is, the brightness of the image reaching the camera 200 is reduced in inverse proportion to the square of the distance. In particular, the half-mirror 600 installed on the optical path to match the image path and the illumination path loses about 1/2 of the amount of light or image passing through the camera in accordance with its characteristics. Since it is impossible to reach 200 clearly, accurate inspection cannot be performed.

Second, as shown in FIG. 2, the light that is finally irradiated to the inspection area 300 becomes oblique light instead of the vertical light by adopting a method of changing the light traveling path using the XY axis movable mirrors 400 and 500. . Such inclined light is not a problem if the object of the inspection area 300 is composed of a flat surface, but when inspecting a printed circuit board mounted with several parts having a large and small height, a clear image is generated by the shadow generated by each part. Since it cannot be obtained, the reliability of the inspection is degraded.

Accordingly, the present invention is expected to increase the inspection work efficiency by minimizing the driving torque and vibration as well as quickly changing the shooting position by changing the shooting position by rotating the X-axis total reflection mirror and Y-axis total reflection mirror. The ultimate goal is to provide a vision inspection apparatus and vision inspection method using a total reflection mirror.

In addition, the present invention is equipped with a fixed direct irradiation method, by increasing the amount of light incident on the camera by providing a vision inspection apparatus and a vision inspection method using a total reflection mirror that can obtain a clear image of the inspection object. There is a purpose.

In addition, by adopting a direct irradiation method to the inspection object as described above, a vision inspection apparatus using a total reflection mirror that can perform accurate inspection by preventing the occurrence of shadows when inspecting objects mounted with large and small parts, such as a printed circuit board and It is an additional purpose to provide a vision inspection method.

1 is an overall configuration diagram for explaining the pre-registered invention.

2 is a configuration diagram showing an operation state of the pre-registered invention.

Figure 3a is a schematic diagram showing the overall configuration of a vision inspection apparatus using a total reflection mirror according to the present invention.

Figure 3b is a block diagram showing the image acquisition operation of the vision inspection apparatus using a total reflection mirror according to the present invention.

4 is a plan view showing the configuration of the independent lighting unit in the vision inspection apparatus using a total reflection mirror according to the present invention.

5 is a conceptual diagram illustrating a vision inspection apparatus using a total reflection mirror according to the present invention.

6 is a flowchart showing a vision inspection method using a total reflection mirror according to the present invention.

Figure 7a is an overall configuration showing another embodiment of a vision inspection apparatus using a total reflection mirror according to the present invention.

Figure 7b is a block diagram showing the image acquisition operation of another embodiment of the vision inspection apparatus using a total reflection mirror according to the present invention.

8 is a conceptual view illustrating another embodiment of a vision inspection apparatus using a total reflection mirror according to the present invention.

9 is a flowchart showing a vision inspection method of another embodiment using a total reflection mirror according to the present invention.

<Explanation of symbols for major parts of drawing>

1,1 ': Vision inspection device 2: Board position control module

3: independent lighting unit 4: shooting position control module

5: subordinate lighting unit 6: camera

7: control unit 8: vision processing unit

21: substrate holder 22, 23: first and second detection sensor

24,25: slope 31: primary lighting

32: field of view securing passage 41: X axis rotation motor

42: Y axis rotation motor 51: Semi-reflective mirror

52: secondary lighting 71: motion controller

72: lighting controller 73: image processor

211: stopper 411: total reflection mirror in X axis 421: total reflection mirror in Y axis

As a specific means of the present invention for achieving the above object,

A substrate position control module for fixing a printed circuit board on which components are mounted at an appropriate inspection position;

An independent lighting unit which is installed directly above the substrate position control module, and includes a primary lamp that primarily illuminates the printed circuit board;

A photographing position control module installed at an upper portion of the independent lighting unit and attaching a total reflection mirror to a shaft of an X-Y axis rotating motor to change a reflection angle to a desired position coordinate of the printed circuit board;

A camera acquiring an image of the printed circuit board reflected by the photographing position control module;

A motion controller for controlling the photographing position control module and the substrate position control module, an illumination controller for controlling the operation of the independent lighting unit, an image processor for controlling the operation of the camera and converting an image incident on the camera into digital data. A control unit; And

It is achieved by having a vision inspection apparatus using a total reflection mirror comprising a; vision processing unit for determining whether or not by reading the image obtained through the camera,

The present invention also provides a vision inspection method comprising: fixing a printed circuit board to an appropriate inspection position through a substrate position control module; Illuminating the printed circuit board in an independent lighting unit; Adjusting an incident angle and a reflection angle through a total reflection mirror attached to an axis of an X-Y rotating motor to transfer an image of the printed circuit board to a camera; Converting an image incident on the camera into digital data; And it is implemented by having a vision inspection method using a total reflection mirror characterized in that the step of determining the good or bad of the mounting parts by reading the image acquired through the camera.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3a is a schematic diagram showing the overall configuration of the vision inspection apparatus using a total reflection mirror according to the present invention, Figure 3b is a block diagram showing the image acquisition operation of the vision inspection apparatus using a total reflection mirror according to the present invention, Figure 4 In the vision inspection apparatus using a total reflection mirror according to the invention, a plan view showing the configuration of the independent lighting unit, Figure 5 is a conceptual diagram for explaining a vision inspection apparatus using a total reflection mirror according to the present invention, Figure 6 according to the present invention This is a flowchart showing the vision inspection method using the total reflection mirror.

3A to 6, the vision inspection apparatus 1 of the present invention performs a vision inspection before the printed circuit board, which has finished surface mounting in the surface mounting line, is moved to the next process through the conveyor of the preceding equipment. It is installed so that. In a preferred installation example, the surface mount line is installed between the surface mounter equipped with the conveyor and the reflow equipment or between the high speed mounter and the release mounter, and is formed in the dead space formed between the conveyor of the front and the following equipment. It is installed by inserting. Accordingly, it is not necessary to change the equipment position of the existing surface mounting line, it can be used as a stand-alone table form without being connected to the pre- and trailing equipment.

At this time, the substrate position control module (2) for controlling the movement of the printed circuit board between the line and the trailing equipment is a conveyor structure for fixing the printed circuit board (PCB) moving along the conveyor of the preceding equipment at a suitable inspection position. As shown in FIG. 3A, the inclined surfaces 24 and 25 are formed at one end and the other end thereof, and the substrate holder 21 is positioned higher than the conveyor of the line and trailing equipment. The substrate holder 21 has a first and second detection sensors 22 and 23 for detecting the flow and position of the printed circuit board (PCB), and a printed circuit board (PCB) based on the detected values of the sensors 22 and 23. A stopper 211 for forcibly stopping the PCB is installed.

As such, the first detection sensor 22, which is installed close to the inclined surface 24 of the substrate holder 21, senses the flow of the printed circuit board (PCB) transferred from the preceding equipment and stops the conveyor of the preceding equipment. It serves to operate the stopper 211 installed in the substrate holder 21. In addition, the second detection sensor 23 performs a function of supplying the printed circuit board (PCB) to be inspected from the preceding apparatus by detecting that the printed circuit board (PCB) on which the inspection is completed is transferred to the following equipment. Accordingly, the printed circuit board to be inspected by the substrate position control module 2 is prepared. (Step S1).

The independent lighting unit 3 is fixedly installed on the upper portion of the substrate position control module 2. The independent lighting unit 3 is configured by arranging a primary lighting lamp (LED lighting lamp or halogen lighting lamp: 31) on the outer circumference of the field of view securing passage 32 passing through the center as shown in FIG. 4, and controlling the substrate position. It is installed as close as possible to the module (2). Accordingly, the light is irradiated onto the printed circuit board PCB on the substrate position control module 2 (step S2).

The photographing position control module 4 is provided directly above the through-hole 32 passing through the center of the independent lighting unit 3. The photographing position control module 4 is composed of XY rotation motors 41 and 42 having total reflection mirrors 411 and 421 attached to shafts, and the XY axis rotation motors 41 and 42 are total reflection mirrors attached to the shafts. The photographing position coordinate is changed by rotating 411 and 421 to change the incident angle. The total reflection mirrors 411 and 421 attached to the X-Y axis rotating motors 41 and 42 reflect the image of the printed circuit board by applying a silver coating mirror that completely reflects the light incident from the printed circuit board.

On the same horizontal line of the total reflection mirror 411 attached to the X-axis rotation motor, a camera 6 for acquiring an image of the inspection part is installed, and such a camera 6 has a motion controller 71 and a light controller 72. And a control unit 7 comprising an image processor 73 and a vision processing unit 8 for reading out an image.

At this time, the motion controller 71 of the controller 7 controls the motor and output means included in the photographing position control module 4 and the substrate position control module 2 by applying a motor controller. In addition, to monitor the entire input and output device of the vision inspection device 1 of the present invention, the lighting controller 72 is applied to the I / O board (ONE-CHIP MICROCONTROLLER) and the peripheral circuit of the independent lighting unit (3), Control off and adjust illuminance.

In addition, the image processor 73 applies the image grabber (GRABER) when the image of the inspection object is incident on the camera 6 through the shooting position control module 4 to adjust the camera 6 or periodically to shoot And convert it into digital data so that it can be processed by the system processor according to the application (step S4).

As such, the motion controller 71, the lighting controller 72, and the image processor 73 constituting the control unit 7 are electrically connected to the vision processor 8 as shown in FIG. 5 to the command signal of the vision processor 8. Is operated by

The vision processing unit 8 manages the photographing position control, the processing of the photographed image and the physical control such as lighting control and substrate position control according to the system control program, and also performs inspection work and data calculation work. It includes an output device controller for outputting the contents and inspection results to the monitor, and an input device controller for the operator to input various items, and reads an image obtained through the camera to determine whether the component is mounted good or bad. (Step S5)

Therefore, when the photographing and inspection is finished while sequentially moving the various inspection positions in the printed circuit board, the conveyor of the substrate position control module 2 is operated to move the printed circuit board to the process equipment after the inspection, such vision inspection. By repeating the method, a continuous inspection of the printed circuit board is performed.

The vision inspection apparatus 1 and the vision inspection method of the present invention change the photographing position by rotating the total reflection mirrors 411 and 421 of the photographing position control module 4 while the camera 6 and the printed circuit board are fixed. Compared to the conventional method of moving a camera or a printed circuit board, the volume of the device itself can be significantly reduced, so it can be suitably used for surface mounting lines having a lot of space restrictions. In addition, as the total reflection mirrors 411 and 421 are rotated in this way, the driving torque is small, and vibrations can be minimized when moving and stopping, and the motor rotation speed for moving the same distance in the substrate is relatively small, so that the movement between the shooting points can be made quickly. Therefore, it is possible to perform a high-speed inspection, there is little vibration added to the inspection object during the inspection can significantly reduce the induction of defects caused by the vibration.

In particular, by implementing the fixed direct irradiation method through the independent lighting unit 3 as shown in Figure 3b and by installing the independent lighting unit 3 as close as possible to the printed circuit board, generated by passing through the half mirror as before It is possible to minimize the light reduction of the illumination source and the light reduction of the image, and to reduce the reduction of the light quantity caused by the distance between the illumination source and the inspection object, thereby improving the reliability of inspection through clear image acquisition. will be.

In addition, by irradiating light from the upper four sides of the printed circuit board through the independent lighting unit 3, there is an advantage that can prevent the shadow of the large and small components mounted on the printed circuit board.

Figure 7a is an overall configuration showing another embodiment of the vision inspection apparatus using a total reflection mirror according to the present invention, Figure 7b is an image acquisition operation of another embodiment of the vision inspection apparatus using a total reflection mirror according to the present invention. 8 is a conceptual diagram illustrating another embodiment of a vision inspection apparatus using a total reflection mirror according to the present invention, and FIG. 9 illustrates a vision inspection method of another embodiment using a total reflection mirror according to the present invention. Flowchart.

7A to 9, in another embodiment of the vision inspection apparatus 1 ′ and the vision inspection method according to the present invention, the subordinate lighting unit 5 is disposed between the camera 7 and the photographing position control module 4. Is installed. The sub-illuminator 5 illuminates the printed circuit board (PCB) through a secondary lamp (laser lamp or halogen lamp), but as shown in FIG. Or with a semi-coated mirror: 51 to the total reflection mirror 411 attached to the X-axis rotation motor 41 of the shooting position control module 4, the light irradiated from the secondary lamp 52 is located on the horizontal line. (Step S2 ')

At this time, the subordinate lighting unit 5 is connected to the above-described lighting controller 72, as shown in Figure 8, the on-off control and the illumination is adjusted.

In addition, the photographing position control module 4 rotates the total reflection mirrors 411 and 421 attached to the axes of the XY axis rotation motors 41 and 42 to change the incident angle of the light irradiated from the subordinate lighting unit 5, thereby illuminating the illumination. In addition to changing the position coordinates, it also changes the angle of reflection, thereby changing the position coordinates.

Accordingly, in another exemplary embodiment of the present invention, as shown in FIG. 7B, an image is obtained in a state where the inspection portion on the printed circuit board is illuminated by the independent lighting unit 3 and the dependent lighting unit for 1 to 2 times. Can be. For example, it can be effectively used when acquiring a special image by irradiating powerful light on a specific part of the inspection object.

Afterwards, the obtained image is reflected through the total reflection mirrors 411 and 421 attached to the axes of the X-Y rotating motors 41 and 42, passes through the semi-reflective mirror 51, and then is transmitted to the camera 6.

As described above, the vision inspection apparatus and the vision inspection method using the total reflection mirror according to the present invention change the photographing position by rotating the XY-axis total reflection mirror of the photographing position control module, thereby minimizing driving torque and vibration as well as photographing. The position change operation can be performed quickly, thereby increasing the inspection work efficiency.

In particular, by providing an independent lighting unit of the fixed direct irradiation method, it is effective to obtain a clear image of the inspection object by increasing the amount of light incident on the camera, and thus adopts a direct irradiation method on the inspection object and the printed circuit board It is effective to perform accurate inspection by preventing the occurrence of shadows during vision inspection of objects mounted with large and small parts.

Claims (8)

A substrate position control module for fixing a printed circuit board on which components are mounted at an appropriate inspection position; An independent lighting unit installed directly above the substrate position control module and provided with a primary lamp for illuminating the printed circuit board; A photographing position control module installed at an upper portion of the independent lighting unit and attaching a total reflection mirror to a shaft of an X-Y axis rotating motor to change a reflection angle to a desired position coordinate on the printed circuit board; A camera acquiring an image of the printed circuit board reflected by the photographing position control module; A motion controller for controlling the photographing position control module and the substrate position control module, an illumination controller for controlling the operation of the independent lighting unit, an image processor for controlling the operation of the camera and converting an image incident on the camera into digital data. A control unit; And Vision inspection apparatus using a total reflection mirror comprising a; vision processing unit for determining whether or not by reading the image obtained through the camera. According to claim 1, wherein the substrate position control module is a conveyor structure, the first and second detection sensors for detecting the flow and position of the printed circuit board and the stopper for forcibly stopping the printed circuit board by the detection value of each sensor Vision inspection apparatus using a total reflection mirror, characterized in that consisting of a substrate fixing having. The vision inspection apparatus of claim 1, wherein the substrate holder has an inclined surface formed at one end and the other end thereof, and is positioned at a position higher than that of the conveyor of the first and second equipments. According to claim 1, wherein the independent lighting unit is installed on the outer circumference of the field of view securing passage 32 passing through the center, the first illumination lamp is arranged to illuminate the printed circuit board from all directions using a total reflection mirror, characterized in that Vision inspection device. The vision inspection apparatus using a total reflection mirror according to claim 1, wherein the independent lighting unit is installed near the upper portion of the substrate position control module (2). A substrate position control module for fixing the printed circuit board to an appropriate inspection position; An independent lighting unit which is installed directly above the substrate position control module, and includes a primary lamp that primarily illuminates the printed circuit board; A photographing position control module installed at an upper portion of the independent lighting unit and attaching a total reflection mirror to an axis of the X-Y rotating motor to photograph and illuminate at a desired position coordinate; The irradiation position on the printed circuit board is changed in association with the photographing position according to the movement of the photographing position control module, and reflects light such as a secondary light to the photographing position control module and transmits the image of the printed circuit board. Subordinate lighting unit provided with a mirror; A camera for obtaining an image of the printed circuit board passing through the semi-reflective mirror; A motion controller for controlling the photographing position control module and the substrate position control module, an illumination controller for controlling the operation of the independent lighting unit, an image processor for controlling the operation of the camera and converting an image incident to the camera into digital data. Control unit consisting of; And Vision inspection apparatus using a total reflection mirror comprising a; vision processing unit for determining whether or not by reading the image obtained through the camera. Fixing the printed circuit board to an appropriate inspection position through the substrate position control module; Illuminating the printed circuit board in an independent lighting unit; Adjusting an incident angle and a reflection angle through a total reflection mirror attached to an axis of an X-Y rotating motor to transfer an image of the printed circuit board to a camera; Converting an image incident on the camera into digital data; And Vision inspection method using a total reflection mirror characterized in that the step of determining the good or bad of the mounting parts by reading the image acquired through the camera Fixing the printed circuit board to an appropriate inspection position through the substrate position control module; Primary lighting the printed circuit board by an independent lighting unit; Through the total reflection mirror attached to the axis of the XY rotation motor to transmit the image of the printed circuit board to the camera while irradiating the secondary illumination reflected to the semi-reflective mirror of the subordinate lighting unit to the desired position coordinate of the printed circuit board. Adjusting an incident angle and a reflection angle; Converting an image transmitted through the semi-reflective mirror of the subordinate lighting unit and incident on the camera into digital data; A vision inspection method using a total reflection mirror, characterized in that the step of determining the good or bad of the mounting parts by reading the image acquired through the camera.