JPH061173B2 - Curved property inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a specularly reflective curved surface body composed of a set of many curved surface elements whose surface curved surface properties are oriented in different directions. The present invention relates to a curved surface property inspection apparatus applied to detect orientation defects, and 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. Regarding the device.

<Prior Art> As a specularly reflective curved surface body having a multi-orientation curved surface, a representative example thereof is a surface shape of a soldering portion of a component mounted on a substrate. Conventionally, this soldering part is
It is inspected by visual inspection, and whether or not the soldering condition is good, that is, the presence or absence of solder, the amount, the solubility, the short circuit, the poor continuity, and the like are determined by this visual inspection.

However, such a method by visual inspection inevitably causes the occurrence of inspection errors, the judgment result varies depending on the inspector, and the inspection processing capacity is limited.

Therefore, in recent years, various automatic inspection devices capable of automatically performing this type of inspection have been proposed.

By the way, the surface shape of the soldered portion is a three-dimensional shape having a three-dimensional spread, and in order to inspect this, it is indispensable to be able to detect three-dimensional shape information.

FIG. 3 shows an example of an automatic inspection apparatus that satisfies this condition. A plate-like slit light 1 is emitted from a light source such as a laser to a soldering portion on a substrate 2. By irradiating the slit light 1, the substrate 2 including the soldered portion
An optical cutting line 3 which is distorted along the three-dimensional shape is generated on the surface of the image pickup device. By checking, the three-dimensional shape of the soldered 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 other portions. Moreover, since the orientation of the surface of the soldered portion is indefinite with respect to the vertical direction of the substrate 2, at least four or more combinations of the light source and the imaging device 4 are required, which complicates the device. And high precision assembly work is required,
There are problems such as high costs.

Therefore, as a method of solving this kind of problem, the surface of the curved surface object to be inspected is irradiated with light having different incident angles, each reflected light image from the surface of the curved surface object is imaged, and the curved surface object is obtained from each imaging pattern. There is a method of detecting the orientation of each curved surface element of. The principle of this method belongs to "active sensing method" which is one of three-dimensional image information detection. That is, this method focuses on the fact that when a light beam having a certain pattern is projected onto the inspection target, the pattern of the reflected light beam obtained from the inspection target is deformed in accordance with the three-dimensional shape of the inspection target. Then, the shape of the inspection target is estimated from the deformation pattern.

FIG. 4 is an explanatory view of the principle of this method, and shows the positional relationship between the detection system including the light projecting device 5 and the image pickup device 6 and the curved surface body 7 to be inspected.

In the figure, when a light beam 8 is projected from the light projecting device 5 onto the surface of the curved body 7 at an incident angle i, a reflected light beam 9 at an angle i ′ (= i) is projected onto the imaging device 6 directly above. It is incident and detected. As a result, it is detected that the curved surface elements of the curved body 7 illuminated by the light flux 8 are oriented at an angle of i with respect to the reference plane 10. Therefore if curved surface 7
If the surface shape of the object is composed of a large number of curved surface elements oriented in different directions such as a soldering surface, it is possible to project light onto the surface of the curved surface body 7 using a plurality of light projecting devices having different incident angles. For example, a group of curved surface elements corresponding to the respective incident angles is detected by the image pickup device 6, and as a result, the orientation of each curved surface element on the surface of the curved body 7 is determined, that is, the surface shape of the soldered portion is determined. Can be detected.

If the light projecting device 5 projects a light beam 8 having an incident angle of 2Δi from i + Δi to i−Δi, a reflected light beam 9 having a width corresponding to the width is detected by the imaging device 6. Become. That is, in this case, it is possible to detect a curved surface element having an angle of inclination of i + Δi to i−Δi with the reference surface 10.

Further, as shown in FIG. 5, if the light projecting device 5 is a ring-shaped device that is installed horizontally with respect to the reference plane 10, what is the curved body 7 with respect to the axis perpendicular to the reference plane 10? Even if there is a rotation angle, the distance between the light projecting device 5 and the curved surface member 7 is constant, and the orientation of the curved surface element in the rotation angle direction is erased. Therefore, only the tilt angle with the reference plane 10 can be detected. become.

Further, as shown in FIG. 5, the light projecting device 5 is provided with a plurality of ring-shaped light emitting bodies 11, 12, 1 having different incident angles to the curved surface body 7.
If it is configured with 3, the luminous fluxes 14 and 1 by the respective light emitters
As described above, the curved surface elements having the orientations corresponding to the incident angles of 5 and 16 can be detected in detail.

Now, the height h of the three ring-shaped light-emitting bodies 11, 12, 13 having a radius of r _n (where n = 1, 2, 3) with respect to the reference plane 10 is set.
If it is installed horizontally at the position _n (n = 1,2,3), the curved surface 7
The incident angles of the respective light beams 14, 15, 16 on
_{n (n} = 1,2,3), and the respective curved surface elements inclined angle is i _n, respectively, in curved body 7 can be detected by the imaging device 6. At this time, since the size of the curved surface element is sufficiently smaller than the total optical path length from each light emitting body 11, 12, 13 to the image pickup device 6 through the surface of the curved surface body 7, let's detect the incident angle, that is, by the following equation. The angle of inclination of the curved surface element is defined.

As a method for inspecting the external appearance of the soldered portion based on the above principle, a method using a white light source for each of the light emitting bodies 11, 12 and 13 has been proposed (JP-A-61-293657).
issue). In this inspection method, in order to distinguish reflected light images from three light emitters 11, 12, 13 having different incident angles with respect to the soldering surface from each other, the light emitters 11, 12,
12 and 13 are turned on and off at different timings with respect to time.

<Problems to be Solved by the Invention> However, in such a method, a memory for storing each image obtained at different light projection timings, an arithmetic unit for arithmetically processing these images as the same visual field image, A lighting device or the like for instantaneously lighting each light emitter is required, which is complicated in terms of technology, and is a problem in terms of cost and reliability.

Therefore, as a method for solving all of the problems of the time sharing method at once, there is a method proposed as an apparatus for inspecting a linear object such as a wire (Japanese Patent Laid-Open No. Sho 61-206).
62-127617). In this method, three primary color light sources of red, green, and blue are used as three light emitters having different incident angles with respect to the inspection target, and red, green, and blue reflected light images from the inspection target are captured by a color television camera. Such a color sensing type image pickup device separates and detects at the same timing.

When this method is applied to an automatic inspection device for soldered parts, it is theoretically possible to detect the curved surface property of the soldered part in a short time, but information on each part on the board (for example, part number, polarity, color Since it is devised to detect peripheral information such as codes) and board pattern information (various marks, etc.) which are indispensable for automatic inspection of board-mounted components, it is very difficult to put the apparatus to practical use as it is.

The present invention has been made in view of the above problems, and by devising such that the irradiation light of each light-emitting body is combined into white light, the curved surface characteristics of a specularly reflective curved surface body such as a soldered part It is an object of the present invention to provide a curved surface property inspecting apparatus that can detect the above in a short time and can also detect the peripheral information that is essential for the actual inspection.

<Means for Solving the Problems> In order to achieve the above object, in the present invention, three ring-shaped light emissions each generating a first hue light, a second hue light, and a third hue light are provided. The body is arranged so that the incident angle of each hue light on the surface of the specularly reflective curved surface body is different, and the reflected light image from the surface of the specularly reflective curved surface body for each hue. A curved surface property inspection device is configured by an image pickup means for picking up an image and a processing means for detecting an inclination angle of each curved surface element having the specularly curved surface body from an image pickup pattern obtained by the image pickup means. There is. Each of the light emitters of the light projecting means has a light emission energy distribution with respect to wavelength so that white light is obtained by combining the respective hue lights, and when the light projecting means combines the hue light of each light emitter. A light amount adjusting means for adjusting the light amount of each light emitter so as to obtain white light is connected.

<Operation> When the first hue light, the second hue light, and the third hue light are emitted from the respective light emitters with different incident angles with respect to the surface of the specularly reflective curved surface body, the surface of the curved surface body is irradiated. The respective reflected light images of the first hue light, the second hue light, and the third hue light are simultaneously separated and detected by the image pickup means. In this case, each light emitting body has a distribution energy of counter wavelength emission which becomes white light due to the constitution of each hue light, and when the hue light from each light emitting body is combined, each light emission becomes white light. Since the amount of light of the body is adjusted, in the solder inspection of mounted parts, etc., add information about the curved surface property of the soldered part,
Peripheral information such as information about parts will also be detected at the same time.

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

The board inspecting apparatus of the illustrated example has components 21S on the positioning board 20S obtained by imaging the positioning board 20S.
Of the inspection area (determination data) and the parameters (inspection data) of the inspection area of each component 21T on the inspected substrate 20T obtained by imaging the inspected substrate 20T are compared, It is for inspecting whether each component 21T is correctly mounted and soldered, and includes an X-axis table shaft 22, a Y-axis table unit 23, a light projecting unit 24, an imaging unit 25, a processing unit 26, and the like. Is included as its composition.

The X-axis table unit 22 and the Y-axis table unit 23 each include a motor (not shown) that operates based on a control signal from the processing unit 26, and the X-axis table unit 22 is driven by the motors to drive the X-axis table unit 22. 25 is moved in the X direction, and the Y-axis table portion 23 moves the conveyor 27 supporting the substrates 20S and 20T in the Y direction.

The substrates 20S and 20T are imaged by the imaging unit 25 while receiving the irradiation light from the light projecting unit 24.

The light projecting unit 24 is provided with three ring-shaped light emitting bodies 28, 29, 30 that generate red light, green light, and blue light, respectively, based on a control signal from the processing unit 26. The respective light emitters 28, 29, 30 are arranged so that the incident angles of the respective hue lights on the inspection object are different.
The mixed light of the three primary colors emitted from 9, 30 is the substrate 20.
It is projected to S, 20T. The imaging unit 25 is the substrate 20.
The reflected light image at S, 20T is obtained and converted into an electric signal. In the case of this embodiment, each of the aforementioned luminous bodies 28, 29, 3
No. 0 uses a structure in which a red light source, a green color filter, and a blue color filter are covered on a white light source. However, it is needless to say that the present invention is not limited to such a configuration as long as it can generate each hue light of the three primary colors. is there.

In addition, the light projecting section 24 is configured so that the substrates 20S, 20
Since it is possible to detect the information (part number, polarity, color code, etc.) about the parts on the T and the board pattern information (various marks, etc.), each light emitter 28, 29, 3
When the light of each hue emitted by 0 is mixed, it is devised so that it becomes a completely white light. That is, each light emitter 28, 2
9 and 30 are composed of light emitters that emit light of red light spectrum, green light spectrum, and blue light spectrum having a light emission energy distribution with respect to wavelength so as to become white light by color mixing, and each light emitter 28, 29, 30 The light amount of each hue light can be adjusted by the image pickup controller 31 so that the red light, the green light, and the blue light emitted from are mixed into white light.

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

The processing unit 26 includes an A / D conversion unit 33, a memory 38, a teaching table 35, an image processing unit 34, a determination unit 36,
X, Y table controller 37, imaging controller 3
1, CRT display unit 41, printer 42, keyboard 4
0, floppy disk device 43, control unit (CPU) 39
In the teaching mode, the color signals R, G, and
B is processed to detect each hue pattern of red, green, and blue for each predetermined area of each component 21S that is in a good soldering state, and a judgment data file is created. Signals R, G, B
Is processed to detect each similar hue pattern in a predetermined area of each component 21T on the substrate to create an inspection data file. Then, the inspected data file is compared with the determination data file, and based on the comparison result, the good or bad of the soldered portion is automatically determined for the predetermined component 21T on the inspected substrate 20T.

FIG. 2 is a cross-sectional view of the solder 44 when the soldering is good, when the component is defective, and when the solder is insufficient, and the image pickup pattern, red pattern, green pattern, and blue in each case. The relationship with the pattern is shown in a list, and since a clear difference appears between any of the hue patterns, it is possible to determine the presence or absence of parts and the quality of soldering.

Returning to FIG. 1, when the color signals R, G, B are supplied from the image pickup section 25, the A / D conversion section 33 converts the color signals R, G, B from analog to digital and outputs them to the control section 39. The memory 38 has a RAM and the like and is used as a work area of the control unit 39. The image processing unit 34 performs image processing on the image data supplied via the control unit 39 to create the inspection data file and the judgment data file, and supplies these to the control unit 39 and the judgment unit 36.

The teaching table 35 is used by the control unit 3 during teaching.
9 stores the judgment data file when it is supplied, and when the control unit 39 outputs a transfer request at the time of inspection, the judgment data file is read out in response to this request, and this is read out by the control unit 39 or 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 inspection data file transferred from the image processing unit 34, and the inspection target substrate 2
For 0T, the quality of the soldering state is determined, and the determination result is output to the control unit 39.

The imaging controller 31 includes an interface that connects the control unit 39 to the light projecting unit 24 and the image capturing unit 25, and based on the output of the control unit 39, each light emitter 2 of the light projecting unit 24.
Controls such as adjusting the light amounts of 8, 29, 30 and maintaining the mutual balance of the respective color light outputs of the color television camera 32 of the imaging unit 25 are performed.

The X, Y table controller 37 includes a control unit 39 and the X
An interface for connecting the axis table unit 22 and the Y-axis table unit 23 is provided, and the X-axis table unit 22 and the Y-axis table unit 23 are controlled based on the output of the control unit 39.

The CRT display unit 41 includes a cathode ray tube (CRT), and when image data, determination results, key input data, and the like are supplied from the control unit 39, this is displayed on the screen. When the printer 42 receives the determination result from the control unit 39,
This is printed out in a predetermined format. The keyboard 40 is provided with various keys necessary for inputting operation information, data regarding the positioning board 20S, data regarding the parts 21S on the positioning board 20S, and the information and data entered through the keyboard 40 are controlled. It is supplied to the section 39.

The control unit 39 includes a microprocessor and the like,
It operates according to the procedure described below.

First, when inspecting a new substrate 20T to be inspected, the control unit 39 controls each unit of the apparatus to turn on the light projecting unit 24 and the image pickup unit 25 in order to execute teaching, and also sets the image pickup condition and the data processing condition. Arrange. Next, the Y-axis table unit 2
When the positioning substrate 20S is set on the control unit 3, the control unit 3
Reference numeral 9 controls the X-axis table unit 22 and the Y-axis table unit 23 to position the positioning substrate 20S, and thereafter, the imaging unit 2
The positioning board 20S is imaged on the display 5. The color signals R, G, B of the three primary colors obtained by this imaging operation are A / D converted by the A / D converter 33, and the conversion result is stored in the memory 38 in real time.

Then, the control unit 39 transfers the image data corresponding to each hue from the memory 38 to the image processing unit 34, and the image processing unit 34 binary-processes the image data of each hue with an appropriate threshold value for each hue. Then, the red, green, and blue patterns are detected. The control unit 39 also controls the image processing unit 34.
Is controlled to check the brightness of each part (such as an electrode) in the image pickup pattern of each part 21S.
The position of the S electrode and the position of the polarity mark are identified.

After that, the control unit 39 creates a determination data file necessary for inspecting the inspected substrate 20T based on the hue patterns and the identification result, and stores the determination data file in the teaching table 35. , Teaching ends.

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

After that, the control unit 39 adjusts the imaging condition and the data processing condition, and then checks whether or not the inspected substrate 20T is set on the Y-axis table unit 23.

If set, the control unit 39 causes the image processing unit 34 to sequentially detect the hue patterns and identify the electrodes and the polar marks, as described above, and then determines the hue patterns and the identification results. Based on this, create a data file to be inspected. Then, the control unit 39 transfers the inspected data file to the determination unit 36, compares the inspected data file with the determined data file, and inspects the inspected substrate 20.
The quality of soldering is determined for the predetermined component 21T on the T, and the determination result and the CRT display unit 41 and the printer 42 are supplied to display and print them out.

<Effects of the Invention> As described above, the present invention is characterized in that each of the ring-shaped light emitters has a different incident angle with respect to the surface of the specularly curved curved surface member.
Since the reflected light image from the surface of the curved body is simultaneously obtained for each hue by irradiating the second and third hue light, the characteristics of the specularly reflective curved body using each hue pattern. Can be detected in a short time. Moreover, each light emitter has an emission energy distribution with respect to wavelength so that a white color is produced by combining the respective lights, and the light amount of each light emitter is adjusted so that the hue light by each light emitter becomes white light when combined. Since it is configured as described above, it is possible to detect the peripheral information that is indispensable in the solder inspection of the mounted component, and the remarkable effect of achieving the object of the invention is achieved, such as the automation of the solder inspection.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the overall structure of a substrate inspection apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the relationship between the quality of a soldering state and a pattern, and FIG. 3 is a conventional soldering method. FIG. 4 is a principle explanatory view showing an automatic state inspection device, and FIGS. 4 and 5 are principle explanatory views showing the principle of the present invention. 24 ... Projector 25 ... Imaging 26 ... Processing 28, 29, 30 ... Light emitter 31 ... Imaging controller

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-61-293657 (JP, A) JP-A-62-127617 (JP, A) JP-A-59-153108 (JP, A)

Claims (1)

[Claims] 1. A ring-shaped three light-emitting body for respectively generating a first hue light, a second hue light and a third hue light,
A light projecting unit which is arranged so that the incident angles of the respective hue lights on the surface of the specularly reflective curved surface body are different, and for capturing the reflected light image from the surface of the specularly reflective curved surface object for each hue. And a processing means for detecting the inclination angle of each curved surface element of the specular curved surface body from the imaging pattern obtained by the imaging means. Each illuminant of the light means has a counter wavelength emission energy distribution such that it becomes white light by combining the respective hue lights, and the light projecting means produces white light when the hue light by each illuminant is combined. A curved surface property inspection device, which is connected with a light amount adjusting means for adjusting the light amount of each light emitter.