JPH01282410A - Curved surface nature inspection device - Google Patents

Abstract

PURPOSE:To achieve the automation in a solder inspection, by a method wherein red, green and blue light are generated separately from three ring-shaped light emitting bodies and the quantity of light is adjusted to emit white light when the light of each light emitting bodies is synthesized. CONSTITUTION:Red, green and blue lights radiated from light emitting bodies 28-30 are mixed and adjusted 31 in quantity of light in terms of hue to emit white light. Reflected light from a substrate 20S or 20T is converted into three primary color signals R, G and B with a color TV camera 32 to be supplied to a processing section 26. At this processing section 26, in a teaching mode, the signals R, G and B are processed for the positioning substrate 20S and red, green and blue hue patterns of a part 21S good in soldering condition are detected to prepare a criterion data file. In an inspection mode, the same operation is performed with a substrate 20T to be inspected to prepare a inspection data file of parts 21T. The inspection data file is compared with the criterion data file to judge the propriety of a soldered part automatically for the parts 21T.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention detects the orientation of each curved surface element in a curved body consisting of a set of a large number of curved surface elements whose surface properties are oriented in different directions. In particular, the present invention relates to a curved surface property inspection apparatus suitable for inspecting the shape of a soldered part of a component mounted on a board.

<Prior Art> A typical example of soldering in a component mounted on a board as a curved body having a multi-oriented curved surface is the surface shape of the part. Conventionally, this soldering part is inspected by visual inspection, and the soldering is in good condition, that is, the presence or absence of solder.

This visual inspection determines the amount, solubility, short circuits, poor continuity, etc.

However, in such a visual inspection method, the occurrence of inspection errors is unavoidable, the judgment results vary depending on the person conducting the inspection, and there is a limit to the inspection processing capacity.

Therefore, in recent years, various automatic inspection devices that can automatically perform this type of inspection have been proposed.

By the way, the surface shape of a soldering part is a three-dimensional shape with three-dimensional expansion, and in order to inspect this, it is essential to be able to detect three-dimensional shape information.

FIG. 3 shows an example of an automatic inspection device that satisfies this condition, in which a plate-shaped slit light 1 is irradiated from a light source such as a laser onto the soldering area on the board 2. By irradiating this slit light 1, soldering is performed on the board 2 including the parts.
A light section line 3 that is distorted along the three-dimensional shape is generated on the surface of the t-layer, and a reflected light image of the light section line 3 is captured by an imaging device 4 to detect the distortion of the T-layer image pattern. By checking the condition, the three-dimensional shape of the soldering part is detected.

However, in the case of this inspection method, only the shape information of the portion irradiated with the slit light 1 is obtained, and it is difficult to grasp the three-dimensional shape of the other portions. Moreover, since the orientation direction of the surface of the soldering part is not fixed with respect to the vertical direction of the substrate 2, at least four combinations of light sources and imaging devices 4 are required, which makes the device complicated. , and requires high-precision assembly work.
There are problems such as high costs.

Therefore, as a method to solve this kind of problem, the surface of the curved surface to be inspected is irradiated with light having different incident angles, and each reflected light image from the surface of the curved surface is imaged, and the curved surface is There is a method of detecting the orientation of each curved surface element. The principle of this method is the "active sensing method", which is a type of three-dimensional image information detection.
It belongs to In other words, this method focuses on the fact that when a light beam with a certain pattern is projected onto an inspection object, the pattern of the reflected light beam obtained from the inspection object undergoes deformation corresponding to the three-dimensional shape of the inspection object. in,
This method estimates the shape of the object to be inspected from the deformation pattern.

FIG. 4 is a diagram explaining the principle of this method, and shows the positional relationship between a detection system consisting of a light projection device 5 and an imaging device 6, and a curved object 7 to be inspected.

In the figure, when the light beam 8 is projected from the light projector 5 onto the surface of the curved surface body 7 at an incident angle i, the angle i' (=i)
The reflected light beam 9 enters the imaging device 6 placed directly above and is detected. As a result, the curved surface 7 illuminated by the light beam 8
This means that it has been detected that the curved surface element of is oriented at an angle of i with respect to the reference plane lO. Therefore, if the surface texture of the curved surface body 7 is composed of a large number of curved surface elements oriented in different directions, such as a soldering surface, the curved surface body 7 can be When light is projected onto the surface of the curved body 7, groups of curved surface elements corresponding to each incident angle are detected by the imaging device 6, and from this, it is possible to determine the orientation of each curved surface element on the surface of the curved surface body 7, that is, whether soldering is performed or not. It is possible to detect what the surface texture of a site is like.

Furthermore, if the light projecting device 5 projects a light beam 8 having a width of 2Δi from an incident angle of i+Δi to i-Δi, a reflected light beam 9 having a width corresponding to the width will be detected by the imaging device 6. become.

That is, in this case, the inclination angle with respect to the reference plane 10 is i+Δ
A curved surface element having an angle width from i to i-Δi can be detected.

Furthermore, if the projector 5 is of a ring shape installed horizontally with respect to the reference plane 10 as shown in FIG. Even if there is a rotation angle, the distance between the light projector 5 and the curved surface body 7 is constant, and the orientation of the curved surface element in the rotation angle direction is erased, so that only the inclination angle formed with the reference plane 10 is detected. become.

Further, as shown in FIG.
3, the luminous flux 14, 15 from each light emitter
．． As described above, a curved surface element having an orientation corresponding to an angle of incidence of 16 can be detected in greater detail.

Now, three ring-shaped light emitters 11, 12, 13 with radius r, (where n = i, 2.3) are placed horizontally at a height h n (n -1+2+3) with respect to the reference plane 10. If installed at
The incident angles of are respectively i, , (n=1.2゜3),
Each curved surface element in the curved surface body 7 having an inclination angle of i can be detected by the imaging device 6. At this time, since the size of the curved surface element is sufficiently small compared to the total optical path length from each light emitting body 11° 12.13 to the ↑layer imager 6 via the surface of the curved surface body 7, the angle of incidence is determined by the following formula, What is necessary is to determine the inclination angle of the curved surface element to be detected.

Based on the above principle, a method using a white light source for each of the light emitters 11, 12 and 13 has been proposed as a method for inspecting the appearance of soldering parts (Japanese Patent Laid-Open No. 61-2936
No. 57). In this inspection method, in order to mutually identify the reflected light images by the three light emitters 11, 12, and 13 having different incident angles with respect to the surface, the soldering
1°12.13 are turned on and off at different timings.

<Problems to be Solved by the Invention> However, such a method requires a memory for storing each image obtained at different light projection timings, an arithmetic device for processing these images as a same visual field image, A lighting device or the like is required to instantaneously turn on each light emitting body, which is technically complex and poses problems in terms of cost and reliability.

Therefore, as a method to solve the problems of such time-sharing methods all at once, there is a method proposed for an apparatus for inspecting linear objects such as wires (Japanese Patent Application Laid-open No. 6
2-127617). In this method, three primary color light sources of red, green, and blue are used as three light emitters with different angles of incidence on the inspection object, and the red, green, and blue reflected light images from the inspection object are captured by a color television camera. They are separated and detected at the same timing using a hue-sensing type imaging device such as this.

If this method is applied to an automatic inspection device for soldering parts, it is theoretically possible to detect the curved surface properties of soldering parts in a short time, but information about each part on the board (e.g. part number, polarity, etc.) is theoretically possible. , color codes, etc.) and board pattern information (various marks, etc.), which is essential for automatic inspection of board-mounted components, has not been devised to detect peripheral information that is essential for automatic inspection of board-mounted components. .

This invention was made by focusing on the above problem, and by devising a way to combine the irradiated light from each light emitting body to produce white light, soldering can quickly change the curved surface properties of curved objects such as parts. It is an object of the present invention to provide a novel curved surface property inspection device that can detect and also detect peripheral information essential for actual inspection.

<Means for Solving the Problems> In order to achieve the above object, the present invention uses red light and green light that have different incident angles on the surface of a curved surface.

A light projecting means for irradiating blue light, an imaging means for capturing an image of reflected light from the surface of the curved surface on each hue side, and a method for determining each curved surface element of the curved surface from the imaging pattern obtained by the imaging means. A curved surface property inspection device is constituted by the processing means for detecting the property. The light projecting means includes three ring-shaped light emitters that generate red light, green light, and blue light, respectively, and each light emitter emits wavelength-paired light such that white light is produced by combining the respective lights. In addition to having an energy distribution, the light projecting means is connected to a light amount adjusting means for adjusting the light amount of each light emitting body so that when the light from each light emitting body is combined, it becomes white light.

<Function> When the surface of the curved body is irradiated with red light, green light, and blue light from each light emitting body at different incident angles, the red, green, and blue reflected light images from the surface of the curved body are captured by the imaging means. are simultaneously separated and detected. In this case, red light from each luminous body.

When green light and blue light are combined, they become white light, so when inspecting solder on mounted components, in addition to information about the curved surface properties of soldered parts, peripheral information such as information about the parts is also detected at the same time. It turns out.

<Embodiment> FIG. 1 shows a schematic configuration of a board inspection apparatus according to an embodiment of the present invention.

The illustrated example of the board inspection apparatus includes each component 21 on the positioning board 20S obtained by imaging the positioning board 2O3.
Comparing the parameters (determination data) of the inspection area of S with the parameters (inspection data) of the inspection area of each component 21T on the board 2OT to be inspected obtained by imaging the board 20T to be inspected, This is for inspecting whether each of these parts 21T is correctly mounted and soldered. Y-axis table section 23. Light projecting section 24° imaging section 25. The entire configuration includes a processing section 26 and the like.

The X-axis table section 22 and the Y-axis table section 23 are each equipped with a motor (not shown) that operates based on a control signal from the processing section 26, and the drive of these motors causes the X-axis table section 22 to operate as an imaging section. 25 in the X direction, and the conveyor 27 on which the Y-axis table section 23 supports the substrates 2O3, 20T is moved in the Y direction.

These substrates 203.20T are imaged by the imaging section 25 while receiving the irradiation light from the light projecting section 24.

The light projecting unit 24 includes ring-shaped light emitters 28 and 29 that respectively generate red light, green light, and blue light based on a control signal from the processing unit 26 and irradiate the object to be inspected at different incident angles.
．． 30, and the substrates 2O3, 2 are illuminated by the mixed light of the three primary colors emitted from these light emitters 28, 29, 30.
0'r is emitted, and an image of the reflected light is obtained by the imaging section 25 and converted into an electrical signal. In this embodiment, each of the light emitters 2B, 29.30 is a white light source and a red light source.

Although a structure in which green and blue filters are covered is used, it is of course not limited to such a structure as long as it generates light of each hue of the three primary colors.

Moreover, this light projecting unit 24 illuminates the substrates 2O3 and 2O under its illumination.
In order to make it possible to detect information about the components on the T (part number, polarity, color code, etc.) and board pattern information (various marks, etc.),
It is designed so that when the light of each hue emitted by 0 is mixed, it becomes completely white light. That is, each light emitting body 28,2
9.30 is constituted by a light emitting body that emits light in a red light spectrum, a green light spectrum, and a blue light spectrum, each having a emission energy distribution with respect to wavelength such that white light is produced by color mixing, and each of the light emitters 28, 29.30 The imaging controller 31 is capable of adjusting the amount of light of each hue so that the red, green, and blue lights emitted from the light are mixed to form white light.

Next, the imaging unit 25 includes a color television camera 32 located above the light projecting unit 24, and
The reflected light from S or 20T is converted into three primary color signals R, G, and B by this color television camera 32 and supplied to the processing section 26.

The processing section 26 includes an A/D conversion section 33. Memory 38° Teaching table 355 Image processing section 34° Judgment section 36. X
, Y table controller 37° imaging controller 31
．． CRT display section 41. Printer 42. Keyboard 40.
Floppy disk device 43. Control '11 section (CPU) 3
9, etc., and when in the teaching mode, the color signal R9G for the positioning board 2O3,
A judgment data file is created by detecting red, green, and blue hue patterns in a predetermined area of each component 213 that has been processed and soldering is in good condition. The color signals R, G, and B are processed to detect similar hue patterns in predetermined areas of each component 21T on the board to create a data file to be inspected. Then, this inspection data file and the judgment data file are compared, and based on the comparison result, the inspection target board 2 is
For the specified part 21T on the OT, the soldering is good.
Automatically determines defects.

Figure 2 shows the cross-sectional form of the solder 44 when the soldering is good, when a component is missing, and when there is insufficient solder, and the imaging patterns in each case: a red pattern, a green pattern, and a blue pattern. It shows the relationship with the patterns in a list, and since there are clear differences between any hue patterns, it is possible to judge the presence or absence of parts and the quality of soldering.

Returning to FIG. 1, when the A/D conversion section 33 is supplied with the color signals R, G, and B from the imaging section 25, the A/D conversion section 33 converts the color signals from analog to digital and outputs them to the control section 39. The memory 38 includes a RAM and the like, and is used as a work area for the control section 39. @The image processing section 34 performs image processing on the image data supplied via the control section 39 to create the above-mentioned inspected data file and judgment data file, and supplies these to the control section 39 and the judgment section 36.

The teaching table 35 is connected to the control unit 3 during teaching.
When the judgment data file is supplied from the control unit 9, it is stored, and when the control unit 39 outputs a transfer request during inspection, the judgment data file is read out in response to this request and sent to the control unit 39 and the judgment unit. 36 etc.

The determination unit 36 compares the determination data file supplied from the control unit 39 at the time of inspection with the data file to be inspected transferred from the image processing unit 34, and determines the quality of the board 2 to be inspected.
At 0T, it is determined whether the soldering condition is good or bad, and the determination result is output to the control section 39.

The imaging controller 31 includes an interface for connecting the control section 39 with the light projecting section 24 and the imaging section 25, and controls each light emitting body 2B of the light projecting section 24 based on the output of the control section 39.
, 29 and 30, and maintains mutual balance between the hue light outputs of the color television camera 32 of the imaging section 25.

The X, Y table controller 37 includes a control section 39 and the
It includes an interface for connecting the axis table section 22 and the Y-axis table section 23, and controls the X-axis table section 22 and the Y-axis table section 23 based on the output of the control section 39.

The CR7 display section 41 is equipped with a cathode ray tube (CRT), and when image data, judgment results, key manual data, etc. are supplied from the control section 39, they are displayed on the screen. When the printer 42 is supplied with the determination result etc. from the control unit 39,
This is printed out in a predetermined format. The keyboard 40 is equipped with various keys necessary for inputting operation information, data regarding the positioning board 203, data regarding the parts 213 on the positioning board 20S, etc., and the information and data entered from the keyboard 40 are controlled. 1 part 39 is supplied.

Regulation? The al1 unit 39 includes a microprocessor and the like, and operates according to the following procedure.

First, when inspecting a new substrate to be inspected 20T, the control section 39 controls each section of the apparatus to execute teaching, turns on the light projecting section 24 and the imaging section 25, and also sets the imaging conditions and data processing conditions. Arrange. Next, Y-axis table section 2
When the positioning board 2O3 is set on the controller 3, the controller 3
9 controls the X-axis table section 22 and the Y-axis table section 23 to position the positioning board 203, and then moves the imaging section 2
5 to image the positioning board 20S. The three primary color signals R, G, and B obtained by this imaging operation are A/D converted by an A/D converter 33, and the conversion results are stored in a memory 38 in real time.

Next, the control section 39 causes the image data corresponding to each hue to be transferred from the memory 38 to the image processing section 34, and the image processing section 34 converts the image data of each hue into binary values using an appropriate threshold value on each hue side. to detect red, green, and blue patterns. Further, the control unit 39 controls the image processing unit 34
is controlled, and each part (
Check the brightness of each part 21S (electrodes, etc.)
Identify the position of the electrode and the position of the polarity mark.

Thereafter, the control unit 39 creates a determination data file necessary for inspecting the board to be inspected 20T based on each of the hue patterns and the identification results, stores this in the teaching table 35, and then , end teaching.

Next, when shifting to the inspection mode, the control unit 39 takes in the date data of the day and the ID number (identification number) of the board to be inspected 20T from the teaching table 35 and the keyboard 40, and reads out the judgment data file from the teaching table 35. , and supplies this to the determination section 36.

Thereafter, the control section 39 checks whether the substrate to be inspected 20T is set on the Y-axis table section 23 after adjusting the imaging conditions and data processing conditions.

If set, the control unit 39 causes the image processing unit 34 to sequentially detect each hue pattern and identify the electrodes and polarity marks, as described above, and then compares each hue pattern with the above identification results. Create a data file to be inspected based on this. Next, the control unit 39 transfers the inspection data file to the determination unit 36, compares the inspection data file with the determination data file, and compares the inspection target data file with the determination data file.
The quality of the soldering is determined for a predetermined component 21T on the T, and the determination results are supplied to the CRT display section 41 and printer 42 to be displayed and printed out.

<Effects of the Invention> The present invention is as described above (i.e., red light, green light, and blue light are emitted from each ring-shaped light emitter at different incident angles to the surface of a curved surface, and the reflection from the surface of the curved surface is reflected from the surface of the curved surface). Since the configuration allows optical images to be obtained simultaneously on each hue side, the properties of the curved surface can be detected in a short time using each hue pattern, and when the red, green, and blue light from each light emitter is combined, white light is generated. Since it is configured to emit light, it is also possible to detect peripheral information that is essential for solder inspection of mounted components, and achieves the remarkable effect of achieving the purpose of the invention, such as realizing automation of solder inspection.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the overall configuration of a board inspection apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the relationship between the soldering condition and the pattern, and FIG. 3 is an explanatory diagram showing the relationship between the soldering condition and the pattern. Attached is a diagram for explaining the principle of an automatic state inspection device, and FIGS. 4 and 5 are diagrams for explaining the principle of the present invention. 24... Light projecting section 25... Imaging section 26.
... Processing unit 28, 29. 30 ... Light emitter 31 ... Imaging controller

Claims (1)

[Claims] Light projecting means for irradiating the surface of a curved body with red light, green light, and blue light having different incident angles, and a means for capturing reflected light images from the surface of the curved body for each hue. A curved surface property inspection device comprising an imaging means and a processing means for detecting the properties of each curved surface element of a curved surface body from an imaging pattern obtained by the imaging means, wherein the light projecting means emits red light and green light. , three ring-shaped light emitters each emitting blue light, and each light emitter has a luminous energy distribution with respect to wavelength such that white light is produced by combining the light from each light emitter. A curved surface property inspection device connected to a light quantity adjusting means for adjusting the light quantity of each light emitter so that the light from the light emitters becomes white light when combined.