JP3243385B2 - Object shape inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting the state of an object such as an electronic component mounted on a printed circuit board. Irradiates the mounting part with stable illumination at all times,
In particular, the present invention relates to an object shape inspection apparatus that accurately and easily detects states such as unsoldering, insufficient soldering, and excessive soldering.

[0002]

2. Description of the Related Art Conventionally, in inspecting a soldered portion of an electronic component or the like mounted on a printed circuit board, a method of irradiating the soldered portion, imaging reflected light thereof with a camera, and judging pass / fail by an image processing technique. Have been proposed. In such a conventional optical inspection device, a fluorescent lamp,
Illumination devices such as halogen lamps are used (see
No. 2-10251). In addition, a red light emitting diode (hereinafter, referred to as LED) is arranged in a ring shape and irradiates from 360 degrees, and furthermore, the illumination intensity of the LED is feedback-controlled by an illuminance sensor to provide a stable illumination system in which the illuminance change is suppressed. Ru configuration the technique mower. In addition, the annular illumination by LEDs is arranged in multiple stages so that the diameter increases in the upper, middle, and lower stages so that the central axes coincide, and a TV camera is installed on the central axis to sequentially switch the illumination of each stage. For inspecting the soldering condition from image data obtained for each stage of illumination (JP-A-4-301549 and JP-A-6-066534).

[0003]

In the case of inspecting a soldered portion by a conventional optical method, if a lighting device such as a fluorescent lamp or a halogen lamp is used, a sufficient reflection intensity can be obtained by the solvent remaining in the soldered portion. In addition, there is a problem to be solved practically, such as shortening of the life of the light source and flickering. In recent years, a technique using infrared light that easily passes through a solvent has become popular. In a conventional device in which a red LED is formed in an annular shape and its irradiation intensity is feedback-controlled using an illuminance sensor, L
Irradiation intensity change due to temperature change of the ED can be suppressed. However, this has a practical problem that the irradiation intensity changes due to a change in temperature or aging of the illuminance sensor and the television camera. Further, in the conventional apparatus in which the LED annular illuminating device is configured in multiple stages, processing of a plurality of image data is required in order to switch and illuminate and image the illumination of each stage having a different angle. Further, the conventional apparatus requires a long inspection time to determine the shape of the solder joint from a plurality of pieces of image data, and excessive determination or erroneous determination occurs depending on a threshold for identifying a defect from the determined shape of the solder joint. There is a practical problem. The present invention solves the above-mentioned problems, and can control the irradiation intensity and the irradiation direction of each annular illumination device, and provides stable illumination that is not affected by temperature changes and aging of optical systems such as illumination devices and cameras. By configuring the system, the shape, structure, and the presence or absence of these objects can be inspected. For example, the shape of the object can be more accurately and easily determined, such as the soldering state of components on an electronic circuit board. An object of the present invention is to provide an inspection device.

[0004]

An object shape inspection apparatus according to the present invention comprises a multi-stage annular illumination device for irradiating an object to be inspected with light at different angles and intensities from above. Irradiation control means for controlling light irradiation by varying the irradiation intensity of each stage of the lighting device, and a surface of the object which is disposed above the lighting device so as to face the object and which is irradiated with light from the lighting device. An imaging device that captures reflected light from the object, and irradiates a light calibration substrate for each lighting device before irradiating the object, and detects the reflected light with the imaging device to obtain a constant amount of reflected light. Intensity control means for controlling the illumination intensity as described above, an image processing apparatus for obtaining the output from the imaging device and analyzing the magnitude of the luminance value of the reflected light from the object, and the illumination intensity by the illumination intensity control means Of the change of the image and by the image processing device And determining the information processing apparatus if the shape of the object from the analysis results is either a steep gradual, characterized by comprising a. Here, the ring-shaped illumination device arranged in multiple stages may be constituted by a fluorescent lamp, a halogen lamp, a light emitting diode or the like.

[0005]

The object shape inspection apparatus of the present invention having the above-described configuration is, for example, a multi-stage illuminating device in which LEDs are arranged on a circle at different angles to obtain an object shape, structure, etc. Since the reflected light from the object can be imaged irrespective of the inclination angle, the shape state of the object can be easily determined. In addition, before inspecting the shape of the object, the annular illumination device of each stage illuminates a light calibration substrate, for example, a white reference plate with a set irradiation intensity for each stage, and images the reflected light. Control the irradiation intensity by performing image processing and comparing and judging with the reference illuminance, so that it is possible to calibrate changes in the irradiation intensity due to temperature changes and aging of the LED and imaging device, and to perform more stable light irradiation Can be. Further, by alternately connecting the LEDs in each stage, it is possible to reduce the illuminance unevenness of the light irradiation surface due to the dispersion of the individual characteristics of the LEDs, and it is possible to more stably inspect the shape state of the object. Further, the object shape inspection apparatus of the present invention can
By arranging lighting devices arranged on a circumference obtained by dividing the ED into multiple parts, for example, two to eight parts, at different angles and installing them in multiple stages, reflected light according to the shape state of the object irrespective of the inclination angle of the shape of the object Can be imaged, so that the shape state, structure, and the like of the object can be easily determined. Furthermore, before inspecting the annular illumination device of each stage for the shape of the object, etc., the white reference plate is illuminated with the set illumination intensity at each stage, in each of the multi-divided directions or collectively, and its reflection is performed. Since the light intensity is controlled by controlling the irradiation intensity by capturing light and performing image processing and comparing it with the reference illuminance, it is possible to calibrate changes in the irradiation intensity due to temperature changes and aging of the LED and the imaging device, and more stable light irradiation It can be performed.

[0006]

Effects of the Invention] According to the shape inspection apparatus of an object of the present invention configured as described above, for example, <br/> irradiation LED annularly body thing to be examined by changing the angle and intensity by the illumination device using Then, the reflected light is picked up by the image pickup device, and data from the luminance value of the part to be inspected to the shape state of the object is created by the image processing device, and the information processing device can detect the shape state of the object. it can. Also, the object of the present invention
According to the body shape inspection device, the irradiation of each annular lighting device
If the brightness value before binarization is large,
Reflection from low-angle lighting, that is,
Reflection from steep parts and high brightness values are small.
Reflection due to illumination from different angles, that is, the shape of the soldered part
Can be detected as a reflection from a gentle part
Therefore, even the solder shape can be detected. In addition, the object shape inspection apparatus of the present invention uses the L of each annular illumination device.
By alternately connecting the EDs, uniform irradiation can be performed without being affected by variations in the characteristics of the intensity of the LEDs. Further, since the irradiation intensity of each annular illumination device is controlled in advance so as to be always constant, the LED, Since stable irradiation can be performed while avoiding the influence of temperature change and aging of the imaging device, a practical operation and effect can be achieved in that the shape state of the object can be more stably and accurately inspected. Further, the object of the present invention
Body shape inspection device, for example, the angle by annular illumination device using a light emitting diode, by irradiating the body material to be examined by changing the direction and the irradiation intensity, and imaging the reflected light by the imaging device imaging The apparatus can detect from the brightness value of the part to be inspected to the shape state of the object.
In addition, the object shape inspection apparatus of the present invention controls the illumination intensity of each annular illumination device in advance so that it is always constant, so that the light emitting diode, the temperature change of the imaging device, and the influence of aging can be avoided in a stable manner. Since the irradiation can be performed, a practical effect can be obtained in which the shape state of the object can be more stably inspected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, representative embodiments of the present invention will be described in detail with reference to the drawings.

First Embodiment The object shape inspection apparatus of the first embodiment is an example applied to a soldering state inspection apparatus, and is basically used for a soldering portion of an electronic component or the like mounted on a printed circuit board. A plurality of annular lighting devices are arranged above the printed circuit board so that the incident angles are different from each other. An imaging device for detecting reflected light from the surface of the soldering portion due to light irradiation of the lighting device is disposed on the central axis of the annular lighting device so as to face the soldering portion. The signal from the imaging device is stored as image data by a data processing determination device, and the soldering state is determined by image processing. Then, the reference illumination intensity of the annular illumination device is radiated at different settings depending on the step, and before the inspection of the soldered portion is performed, the amount of light reflected by the white reference plate is detected by the imaging device and always becomes the reference illumination intensity. In this manner, the current is controlled by controlling the current flowing through the LED. That is, the object shape inspection apparatus of the first embodiment is particularly applied to a soldering state inspection apparatus for detecting the presence / absence of solder in a soldering portion of a chip component mounted on a printed circuit board and the lack of solder. It is. FIG. 1 is a configuration diagram illustrating an object shape inspection apparatus according to a first embodiment. In FIG. 1, a printed circuit board 20 on which a chip component 10 is mounted and soldered is placed on a two-axis moving table 33 composed of an X-axis stage 31 and a Y-axis stage 32, and a circle having a diameter gradually increasing above the table. Ring lighting system
41, 42, 43, and 44 are arranged, and an imaging device 50 is arranged on the central axis. In the object shape inspection apparatus of the first embodiment, the X-axis stage 31 and the Y-axis stage 32 are connected to the positioning device 30, and the positioning device 30 moves the position of the printed circuit board according to a command from the information processing device 70. It is configured to control. In addition, the annular lighting device 4
1, 42, 43, and 44 are connected to the illuminance control device 40, and the illuminance control device 40 controls the lighting, extinguishing, irradiation intensity, and the like of each annular lighting device according to a command from the information processing device 70. Have been. Further, the imaging device 50 is an image processing device 60.
The transfer of image data and image processing by the imaging device 50 are performed on the image processing device 60 by a command of the information processing device 70, and the result is transferred to the information processing device 70 to obtain a desired soldering state. It is configured to make a comparison determination.

FIG. 2 is a sectional view showing the details of the soldered portion 12 of the chip component 10 to be inspected after being mounted and soldered on the printed circuit board 20. In FIG. 2, a pattern electrode 21 is formed on a printed circuit board 20, and a lead electrode 11 of the chip component 10 is fixed via a soldered portion 12 to be connected to the pattern electrode 21. In the soldering portion 12 of such a chip component 10, the irradiation light 41a from the annular lighting device 41 is irradiated by the soldering portion 12 in the direction shown in FIG.
a is the irradiation light 43a from the annular lighting device 43 in the direction in FIG. 2 by the soldering unit 12, and the irradiation light 43a from the annular lighting device 44 is the direction in FIG.
The light 44a is reflected by the soldering section 12 in the direction shown in FIG. In the first embodiment, the light irradiation angle on the soldering portion 12 is 20 to 50 °.

The apparatus for inspecting the shape of an object according to the first embodiment having the above-described structure, when irradiating the soldering section 12 with light, irradiates the soldering section 12 with irradiation light 44a having a low angle like an annular lighting device 44. Are reflected in the direction of the image pickup device 50 at a portion where the shape of the image is steep. Further, the irradiation light 41a having a high angle, such as the annular illumination device 41, is reflected in the direction of the image pickup device 50 at a portion where the shape of the soldered portion 12 is gentle. For this reason, the object shape inspection device of the first embodiment uses the imaging device 50 to generate reflected light corresponding to the shape of the soldered portion by the light irradiation of the annular illumination devices 41, 42, 43, and 44 whose angles are changed. Can be detected. Note that, in the light irradiation shown in FIG. 2, the illumination value of each annular lighting device is not saturated so that the luminance value when the reflected light from the soldered portion by the annular lighting device is detected by the imaging device 50 is not saturated. The irradiation intensity is set in advance. At this time, if the irradiation intensity of the upper annular illumination device is too high, the influence is reflected by the pattern of the printed circuit board or the chip component, so that the irradiation intensity is set to be weak. In other words, by setting the irradiation intensity of the annular illumination device so that the luminance value of the reflected light from the soldering portion 12 becomes weaker from the lower stage to the upper stage within a range where the luminance value of the reflected light does not become a specific value or less, depending on the chip component or the like. The reflection characteristics of the soldered portion 12 can be obtained while avoiding the influence of reflection.

Here, in the light irradiation by the annular illuminating device, the reflected light is sequentially radiated for each stage, and the reflected light is taken.
It is conceivable that the shape of the soldered portion 12 is obtained from a plurality of image data captured by 50. However, in the device of the first embodiment, the light irradiation is performed simultaneously by all the annular illuminating devices, and the reflection characteristic of the soldered portion is detected by the imaging device 50 at one time. That is, since a luminance value equal to or greater than a specific value is detected depending on the presence or absence of solder, it is possible to determine by processing the luminance value. In addition, since the illumination intensity of the annular illumination device of each stage is different, the luminance value of the reflected light from the portion where the soldering portion 12 is steep is high, and the luminance value of the reflected light from the portion where the soldering portion 12 is gentle. Is low, and the brightness
Can be determined. And the soldering part
The details of the determination of the soldering portion by the image processing of the reflected light when irradiating 12 will be described later, and here, the characteristics of the annular illumination device will be described in detail.

In the annular illumination device of each stage, a plurality of LEDs are arranged on the circumference so that light enters the printed circuit board 20 at an angle of each stage. Here, in order to irradiate light with the annular illumination device, it is necessary to supply a current to each LED. Usually, all the LEDs are connected in series for each annular lighting device, and current is supplied from the same power supply.
However, even though the same current flows through each LED, illuminance unevenness occurs on the irradiation surface due to variations in the characteristics of the individual LEDs. For this reason, a method of individually adjusting each LED can be considered, but there is a problem that an adjustment circuit becomes enormous. Thus, in the first embodiment, the irradiation intensity is controlled by two circuits by alternately connecting the LEDs in series. By configuring the annular illumination device as described above, it is possible to irradiate the irradiation surface with uniform illuminance,
It enables more stable inspection.

[0012] In the ring-shaped illuminating device constituted by using the LED, the characteristics of the LED change due to the temperature change, and the irradiation intensity changes. For this reason, in the first embodiment, a white reference plate (not shown) is irradiated before the inspection of the printed circuit board, and the current is controlled based on the luminance value of the reflected light so that the irradiation intensity is always constant. Controlling. That is, the total sum of the brightness values of the reflected light from the reference plate when the white reference plate is illuminated is set in advance for each of the two LED circuits of the annular lighting device of each stage, and the lowermost stage is first set. The light is emitted by one of the LED circuits of the annular illumination device 44, the reflected light is detected by the imaging device 50, and the image processing device 60 calculates the sum of the luminance values in the imaging region of the imaging device 50. The result is compared with the reference value by the information processing device 70, and when it is lower than the reference, the current flowing to the LED is increased, and when it is higher than the reference, the illuminance control device 40 is controlled to decrease the current flowing to the LED. I do. Further, the irradiation intensity of the other LED circuit of the annular illumination device 44 is controlled in the same manner, and control is sequentially performed on the other annular illumination devices.

As described above, by controlling the irradiation intensity of the annular illuminating device constituted by the LEDs, stable light irradiation which is not affected by temperature changes and aging of the LEDs is performed. Further, the effects of temperature changes and aging of the imaging device 50 can be calibrated at the same time. In the first embodiment, a white plate as a reference for controlling the irradiation intensity is installed in an apparatus free from the influence of dust or the like. Can also be applied.

Hereinafter, the operation of the object shape inspection apparatus according to the first embodiment will be described in detail. In FIG. 1,
Printed circuit board on which chip components 10 to be inspected are mounted
The moving table 33 on which the 20 is mounted is fixed to a two-axis moving mechanism including an X-axis stage 31 and a Y-axis stage 32. A white plate (not shown) is also fixed to the moving table 33. When the inspection is started by an external operation (not shown), first, the white plate, on which the positioning device 30 is fixed on the moving table 33, is instructed by the information processing device 70 so that the annular lighting device and the imaging device 50 The X-axis stage 31 and the Y-axis stage 32 are controlled so as to be located on the center axis. Secondly, one of the alternately connected LEDs of the lowermost annular illumination device 44 is turned on at a predetermined irradiation intensity in accordance with a command from the information processing device 70, and the reflected light is detected by the imaging device 50 to perform image processing. The device 60 calculates the sum of the luminance values in the imaging region, compares the result with the reference value in the information processing device 70, and controls the current flowing through the LED. Further, the same control is performed for the other LED and the other annular illumination device.

Third, the X-axis stage 31 and the Y-axis stage 32 are controlled so that the inspection target area of the printed circuit board 20 is positioned on the central axis of the imaging device 50 in accordance with a command from the information processing device 70. Fourth, each of the annular lighting devices is turned on by the illuminance control device 40 with the current value previously controlled by a command from the information processing device 70. Fifth, the imaging device 50 detects reflected light from the inspection target region, and performs image processing based on an algorithm determined by the image processing device 60. Sixth, the state of soldering is determined based on the processing result of the image processing device 60, and the third to fifth operations are repeated so as to perform the inspection of the next inspection target area. Seventh, when the processing of all the inspection target areas is completed, the information processing device 70 displays the inspection result of each soldering part.

The display of the above inspection results is mainly based on displaying defective portions such as unsoldered or insufficiently soldered by an image and a position on a display, and may also display a judgment level described later. It is also possible to print out the inspection results and manage the files. The above is the first
This is a basic operation of the object shape inspection apparatus according to the embodiment, and the determination of the soldering state is performed by the following image processing. An inspection area 100 is set in advance according to the pattern electrodes 21 of the printed circuit board to be inspected for each inspection area as shown in FIG. Then, the luminance value of the reflected light in the inspection area is processed by the image processing device 70. For example, binarization is performed by determining that there is no solder when the brightness value is less than a preset brightness value and by using solder when the brightness value is equal to or greater than the preset brightness value, and calculates the number of pixels that are determined to have solder. If the number of pixels is equal to or greater than the specific value A, the soldering state is determined to be normal, and if the number of pixels is equal to or less than the specific value B, it is determined to be unsoldered. In other words, when the bonding area of the soldered portion is large, the number of detection pixels increases, and when the bonding area is small, the number of detection pixels decreases, so that it is possible to make a determination corresponding to the bonding area. That is, the specific value A of the number of pixels
And B are joined by solder, but their area is small and can be regarded as solder shortage. In addition, since the illumination intensity of each annular illumination device is different, the one having a large luminance value before binarization is reflected by illumination from a low angle, that is, the reflection and luminance value from a portion where the shape of the soldered portion is steep. When the shape is small, it can be detected as reflection by illumination from a high angle, that is, reflection from a portion where the shape of the soldered portion is gentle, so that even the shape of the soldered portion can be detected.

In the first embodiment, an inspection area is set for each electrode to be inspected, and all inspections are performed by controlling the position of the printed circuit board on the moving table 33 with the X-axis stage 31 and the Y-axis stage 32. It is possible. Further, even if the printed board is displaced during the position control, the position correction is always performed by the image processing device 70, so that a stable inspection can be performed. In the first embodiment, a plurality of light emitting diodes as an annular lighting device are alternately connected in series. However, the present invention is not limited to this. In addition, the light emitting diodes may be connected in parallel or individually controlled by software. Can also. Also, the first
In the embodiment, the soldering state inspection apparatus has been described in detail, but is not limited to the inspection of the bonding state and the bonding shape in the soldered portion, the structure, etc. The present invention can be applied to inspections of structures and the like.

[0018]

Second Embodiment Next, an object shape inspection apparatus according to a second embodiment will be described in detail with reference to the drawings. The object shape inspection apparatus according to the second embodiment has a circumference of 4 degrees so that an incident angle is different with respect to a soldered portion such as an electronic component mounted on a printed circuit board.
A plurality of divided annular lighting devices are arranged above a printed circuit board. The imaging device detects reflected light from the surface of the soldering portion due to light irradiation of the lighting device, and is arranged on the center axis of the annular lighting device so as to face the soldering portion. The data processing determination device is configured to store a signal from the imaging device as image data and determine a soldering state by image processing. For this reason, the soldering state simple inspection device of the second embodiment irradiates the white reference plate with the annular lighting device step by step or in four divided directions or collectively before inspecting the soldered portion. In addition, the configuration is such that the amount of reflected light is detected by the imaging device and the current flowing through the LED is controlled so as to always maintain the reference irradiation intensity. The apparatus for inspecting the shape of an object according to the second embodiment is particularly adapted to the presence / absence of solder in the soldering portion corresponding to a predetermined arrangement direction of the soldering portion of the chip component mounted on the printed circuit board.
The present invention is applied to detection of under-excess, over-excess, and the like. FIG. 4 is a configuration diagram showing an object shape inspection apparatus according to the second embodiment. In FIG. 4, the substrate 20 on which the chip component 10 is mounted and soldered is placed on a two-axis moving table 53 composed of an X-axis stage 51 and a Y-axis stage 52, and a circle having a diameter gradually increasing above the table. Ring lighting system
In this configuration, 81, 82, 83, and 84 are arranged, and the imaging device 90 is arranged on the central axis. Substrate on moving table 53
An optical calibration plate 30 is arranged in front of 20, and a dust removing device 40 is installed above the optical calibration plate 30. The X-axis stage 51 and the Y-axis stage 52 are connected to a positioning device 50,
The positioning device 50 is controlled by the information processing device 110
In addition, the movement of the position of the optical calibration plate 30 is controlled.

The annular lighting devices 81, 82, 83, 84 are connected to an irradiation angle / direction switching device 70, and are turned on, off, and illuminated by instructions from the information processing device 110. Controls switching of angle and irradiation direction. Further, the irradiation angle / direction switching device 70 is connected to the irradiation intensity control device 60, and the irradiation intensity control device 60 operates so that the irradiation intensity becomes in accordance with the command of the information processing device 110, and the irradiation value is controlled by the control value. Each annular illumination device is controlled by the angle / direction switching device 50. The imaging device 90 is connected to the image processing device 100, and the image data is transferred and processed by the imaging device 90 to the image processing device 100 according to a command from the information processing device 110, and the result is transferred to the information processing device 110. Then, a comparison is made with the desired soldering state. FIG. 5 is a diagram showing a more detailed configuration of the annular lighting device in the above configuration. For example, the uppermost annular lighting device 81 is divided into four so that its circumference is divided into four equal parts. , Each of which comprises a light emitting diode group 811, 812, 813, 814. The light emitting diodes of each light emitting diode group are connected in series, and are lit with the same current. Further, each light emitting diode group is connected to an irradiation angle / direction switching device 70, and is controlled to be turned on / off in any combination by a control value of the irradiation intensity control device 60. An inspection apparatus for a soldering state using the apparatus of the second embodiment having the above configuration will be described below.
FIG. 6 is a cross-sectional view showing the details of the soldered portion 12 of the chip component 10 to be inspected after being mounted and soldered on the substrate 20. In FIG. 6, a pattern electrode 21 is formed on a substrate 20, and a lead electrode 11 of the chip component 10 is fixed via a soldered portion 12 to be connected to the pattern electrode 21. The soldering part 12 of such a chip component 10
6, the irradiation light 81a from the annular lighting device 81 is directed in the direction in FIG. 6 by the soldering portion 12, and the irradiation light 82a from the annular lighting device 82 is
In the middle direction, the irradiation light 83a from the annular lighting device 83 is
The irradiation light 84a from the annular illumination device 84 in the direction shown in FIG. 6 by the soldering unit 12 is reflected by the soldering unit 12 in the direction shown in FIG. In this embodiment, the light irradiation angle on the soldering part 12 is 20 to 50 °.

In the apparatus of the second embodiment having the above-described structure, when irradiating the soldering portion 12 with light, the annular illumination device 84 is used.
Irradiation light 84a having a low angle as described above is reflected in the direction of the image pickup device 50 at a portion where the shape of the soldering portion 12 is steep. Further, the irradiation light 81a having a high angle like the annular illumination device 81 is reflected in the direction of the imaging device 90 at a portion where the shape of the soldering portion 12 is gentle. For this reason, the apparatus of the second embodiment has annular lighting devices 81, 82, 8
The reflected light corresponding to the shape of the soldered portion can be detected by the imaging device 90 by the light irradiation of 3, 84. In the light irradiation of FIG. 6, the illumination intensity of each annular illumination device is adjusted so that the luminance value when the reflected light from the soldered portion by each annular illumination device is detected by the imaging device 90 is not saturated. It is set in advance by the control device 60.
At this time, if the irradiation intensity of the upper annular illumination device is too high, the influence of reflection by the pattern of the substrate or the chip component occurs, so that it is better to set the irradiation intensity to be weak. That is, in the device of the second embodiment, the irradiation intensity of the annular lighting device
The brightness is set so that the intensity decreases from the lower direction to the upper direction within a range in which the luminance value of the reflected light from the light source does not fall below the specific value.
As a result, the device of the second embodiment can obtain the reflection characteristics of the soldered portion 12 while avoiding the influence of the reflection by the chip component and the like.

In the light irradiation by the annular lighting device, it is conceivable that the shape of the soldering portion 12 is obtained from a plurality of image data by irradiating the light sequentially for each stage and capturing the reflected light by the image pickup device 90. However, in the second embodiment, the reflection characteristic of the soldered portion is detected by one image pickup by the image pickup device 90 by simultaneously irradiating the light with all the annular lighting devices. That is, since a luminance value equal to or more than a specific value is detected depending on the presence or absence of solder, it is possible to determine by processing the luminance value. In addition, since the illumination intensity of the annular lighting device of each stage is different, the luminance value of the reflected light from the portion where the soldering portion 12 is steep is high, and the luminance value of the reflected light from the portion where the soldering portion 12 is gentle is As a result, the shape of the soldered portion 12 can be determined from the intensity of the luminance value.
The details of the determination of the soldering portion by the image processing of the reflected light when the soldering portion 12 is irradiated as described above will be described later, and here, the features of the lighting device method will be described in detail.

In the annular illuminating device 80 constituted by using the light emitting diodes, the characteristics of the light emitting diodes change due to the temperature change, and the irradiation intensity changes. For this reason, in the second embodiment, the optical calibration plate (white plate) 30 installed on the moving table 53 is first moved to below the center of the dust removing device 40 before the inspection of the substrate 20 is performed. After the movement is completed, the dust removing device 40 blows air to the optical calibration plate 30 according to a command from the information processing device 110 to remove dust and the like on the surface. The second
In the embodiment, the dust removing device 40 is blown with air, but may be brushed with a soft cloth or the like. After the dust is removed, the optical calibration plate 30 is moved by the positioning device 50 so as to be below the center of the annular illumination device 80. After the movement is completed, the light emitting diode of the annular illumination device 80 is turned on with the control value determined by the irradiation intensity control device 60 according to a command from the information processing device 110, and the irradiation intensity is calibrated. In other words, control is performed so that the intensity of light reflected from the optical calibration plate is always constant. That is, the total sum of the luminance values of the reflected light when the light calibration plate 30 is irradiated is set in advance for each of the annular illumination devices in each stage, and the illumination is performed by the lowermost annular illumination device 84 first. Then, the reflected light is detected by the imaging device 90, and the image processing device 100 calculates the sum of the luminance values in the imaging region of the imaging device 90. The result is stored in the information processing device 11
The irradiation intensity control device 60 is compared with the reference value by 0 so that the current flowing through the light emitting diode is increased when the value is lower than the reference, and the current is decreased when the value is higher than the reference. The irradiation intensity control device 60 is configured by a feedback circuit so that the current value is instructed. By performing this control for each annular lighting device at each stage, stable light irradiation is performed without being affected by temperature changes and aging of the light emitting diodes. Further, the effects of temperature change and aging of the imaging device 90 can be calibrated at the same time. In the second embodiment, the calibration is performed for each annular lighting device in each stage. However, the calibration can be performed for each of the four divided light emitting diode groups, and more accurate calibration can be performed.

Next, the operation of the object shape inspection apparatus according to the second embodiment will be described in detail. In FIG. 4, the moving table 53 on which the substrate 20 on which the chip component 10 to be inspected is mounted is mounted is fixed to a two-axis moving mechanism including an X-axis stage 51 and a Y-axis stage 52. When the inspection is started by an external operation (not shown), first, the position of the positioning device 50 is fixed by the instruction of the information processing device 110 to the optical calibration plate 30 on the moving table 53, and the dust removing device 40 is stopped. X-axis stage 51 to be positioned
And the Y-axis stage 52 is controlled. Second, information processing device
In response to the command 110, the dust removing device 40 blows air onto the optical calibration plate 30 to remove dust and the like on the surface. Thirdly, the positioning device 50 is turned on by the optical calibration plate according to a command from the information processing device 110.
X so that 30 is located on the center axis of the annular illumination device 80.
The axis stage 51 and the Y-axis stage 52 are controlled. Fourth, the irradiation intensity control device 60 and the irradiation angle / direction switching device 70 turn on the lowermost annular illumination device with a predetermined irradiation intensity and light emitting diode group according to a command from the information processing device 110. Fifth, in response to a command from the information processing device 110, the reflected light from the optical calibration plate 30 is picked up by the image pickup device 90 and transferred to the image processing device 100 to calculate the sum of the luminance values.

Sixth, the information processing device 110 compares and determines the numerical value calculated in the fifth operation with a predetermined reference value. If the value is low, the command value to the irradiation intensity control device 60 is increased. Operates to decrease the command value, and performs the fourth and fifth controls again to control the irradiation intensity to be constant. This operation is performed for each annular lighting device in each stage or each light emitting diode group. Seventh, information processing device 110
The positioning device 50 controls the X-axis stage 51 and the Y-axis stage 52 so that the inspection site of the substrate 20 is located on the central axis of the annular illumination device 80 and the imaging device 90 in response to the command. Eighth, each annular illumination device is turned on by the illuminance control device 60 and the illumination angle / direction switching device at the illumination intensity set in the fourth to seventh operations by a command from the information processing device 110. Ninth, the imaging device 90 detects reflected light from the inspection target area, and performs image processing based on an algorithm determined by the image processing device 100. Tenth image processing device 90
The soldering state is determined based on the processing result of the above, and the seventh to ninth operations are repeated so as to inspect the next inspection target area. Eleventh, when all the inspection target areas have been processed, the information processing apparatus 110 displays the inspection result of each soldered portion.

The above-described inspection results are mainly displayed by displaying defective portions such as unsoldered, under-exposed, and over-exchanged images and positions on a display, and may also display a judgment level described later. It is also possible to print out the inspection results and manage the files. The above is the basic operation of the object shape inspection apparatus according to the second embodiment, and the determination of the soldering state is performed by the following image processing. The inspection area 200 is set in advance according to the pattern electrodes 21 of the printed circuit board to be inspected for each inspection target area as shown in FIG. 7, and the luminance value of the reflected light in the inspection area is processed by the image processing device 110. Do. For example, binarization is performed by determining that there is no solder when the brightness value is less than a preset brightness value and by using solder when the brightness value is equal to or greater than the preset brightness value, and calculates the number of pixels that are determined to have solder. If the number of pixels is equal to or greater than the specific value A, the soldering state is determined to be normal, and if the number of pixels is equal to or less than the specific value B, it is determined to be unsoldered. That is, as shown in FIGS. 8, 9, and 10, when the bonding area of the soldered portion is large, the number of detection pixels increases, and when the bonding area is small, the number of detection pixels decreases. It becomes possible. If complemented by force, an intermediate state between the specific values A and B of the number of pixels can be regarded as an insufficient amount of solder which is joined by solder but has a small area.

The apparatus for inspecting the shape of an object according to the second embodiment can easily detect unsoldering and insufficient soldering as described above. However, detection of excessive soldering as shown in FIG. It is not possible to make a simple determination simply by using For this reason, taking advantage of the fact that the illumination intensity of each annular illumination device is different, those with a large luminance value before binarization are reflected from illumination from a low angle, that is, from the portion where the shape of the soldered portion is steep. The reflection and the luminance value of which are small can be detected as reflection by illumination from a high angle, that is, reflection from a portion where the shape of the soldered portion is gentle, and the shape of the soldered portion can be determined and determined. However, there may be cases where accurate determination cannot be made depending on the processing of a plurality of image data and the threshold for shape determination. But,
In the second embodiment, the following configuration is adopted so that this can be determined easily and accurately. That is, the excess solder part is shown in FIG.
As shown in (2), a raised circular portion is also formed on the electrode of the chip component, and the raised portion has an inclination in a direction opposite to the normal soldering state. Focusing on this feature, the annular lighting device of each stage is configured to be divided into four parts, so that the feature of the excessive solder portion can be easily extracted by performing divided irradiation. That is, FIG.
In the annular lighting device divided in the longitudinal direction of the chip component as shown in (1), only the light emitting diode group opposing the excessive solder portion is turned on. When the soldering state is normal, unsoldered, or insufficient, the image obtained due to reflection as shown in FIGS. 8 and 9 becomes dark. On the other hand, in the case of excess solder, an image in which the excess portion is bright is obtained because the excess portion reflects light from the inclined surface opposite to the irradiation direction of the circular portion formed on the electrode of the chip component. Excessive soldering can be easily determined based on the presence or absence of the brightness.

Further, the shape inspection apparatus object of the present second embodiment, in order arrangement direction of the chip component are the same direction or the + character direction by restriction of the component mounting apparatus, divided into four illumination apparatus annular By setting the axes together in advance, it is possible to determine the excess solder simply by simply switching the irradiation direction. Further, in the second embodiment, an inspection area is set for each electrode to be inspected, and the position of the substrate 20 on the moving table 53 is controlled by the X-axis stage 51 and the Y-axis stage 52, so that all inspections are performed. Is possible. Further, even if a displacement of the substrate 20 occurs during the position control, the position correction is always performed by the image processing device 70, so that a stable inspection can be performed. In addition, the object shape inspection apparatus according to the second embodiment has substantially the same operation and effect as the first embodiment. In addition, the object shape inspection apparatus according to the second embodiment makes the multi-divided illumination device multi-colored, for example, by alternately arranging red, blue, red, and blue in multi-colors, so that the excess part of the soldering part is obtained. Inspection of multicolor identification such as red for the excess part and blue for the soldered part can be performed. Furthermore, the In the respective embodiments, for example, by arranging a soldering portion and a white board to be inspected in the conveying line alternately, you can always perform optical calibration efficiency good Ku.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part showing a soldering part in the first embodiment device.

FIG. 3 is an enlarged plan view of a main part showing a soldering part in the first embodiment device.

FIG. 4 is a block diagram showing an apparatus according to a second exemplary embodiment of the present invention.

FIG. 5 is an enlarged plan view of a main part showing an annular illumination device in the device of the second embodiment.

FIG. 6 is an enlarged sectional view of a main part showing a soldering part in the device of the second embodiment.

FIG. 7 is an enlarged plan view of a main part showing a soldering part in the device of the second embodiment.

FIG. 8 is an enlarged view of a main part showing a cross section and a plane of an unsoldered portion in the device of the second embodiment.

FIG. 9 is an enlarged view of a main part showing a cross section and a plane of an under-soldered portion in the device of the second embodiment;

FIG. 10 is an enlarged view of a main part showing a cross section and a plane of a normal soldering part in the device of the second embodiment.

FIG. 11 is an enlarged view of a main part showing a cross section and a plane of an excessive soldering portion in the device of the second embodiment.

FIG. 12 is a cross-sectional view of a main part of an excessive soldering portion of the multi-segment lighting device of the second embodiment.

FIG. 13 is a cross-sectional view of a main part of a normal soldering portion of the multi-segment lighting device of the second embodiment.

FIG. 14 is a cross-sectional view of a main part of an excessive soldering portion by the multi-segment lighting device of the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Chip component 12 Solder part 20 Printed circuit board 33, 53 Moving table 41, 42, 43, 44, 81, 82, 83, 84 Circular lighting device 50, 90 Image pickup device 60, 100 Image processing device 70, 110 Information Processing device 40 Lighting control device 60 Lighting intensity control device 70 Irradiation angle / direction switching device 30, 50 Positioning device

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Takayuki Kato 41 Toyota Chuo R & D Laboratories Co., Ltd. 41 at Chukku Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture. (72) Inventor Yuchi Yamanouchi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tomoyuki Watanabe 1 Toyota Town, Toyota City, Aichi Prefecture Examiner, Toyota Motor Corporation Takuya Okada (56) References JP-A-6-300702 (JP, A) JP-A-3-158065 (JP, A) JP-A-54-128756 (JP, A) JP-A-2-254308 (JP, A) JP-A-6-331564 (JP, A) JP-A-3-175309 (JP, A) JP-A-64-68606 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01B 11 / 00-11/30 102 G01N 21/84-21/958

Claims (1)

(57) [Claims] 1. An annular illumination device having a multi-stage arrangement for irradiating an object to be inspected with light at different angles and intensities from above, and irradiating light by varying the illumination intensity of each stage of the illumination device. An illumination control means for controlling the illumination device; an imaging device disposed above the lighting device so as to face the object; and an imaging device for capturing light reflected from the surface of the object by light irradiation of the lighting device; Irradiation intensity control means for irradiating the optical calibration substrate for each illumination device of each stage, detecting the reflected light with an imaging device, and controlling the irradiation intensity so that the amount of reflected light becomes a constant reflected light amount, the imaging device An image processing device that obtains an output from the object and analyzes the magnitude of the brightness value of the reflected light from the object; and a change in the irradiation intensity is corrected by the irradiation intensity control means, and the object is analyzed based on the analysis result by the image processing device. Shape is steep or gentle Shape inspection device of an object, comprising the, the information processing apparatus determines.