JPH08222896A - Lighting equipment for mounting machine - Google Patents

Abstract

PURPOSE: To provide an illuminator for a mounting machine, which can prevent the recognition rate of a camera device against alignment marks formed on printed boards from lowering due to reflected light from the specular surfaces of the marks. CONSTITUTION: An illuminator for a mounting machine is constituted of a camera device 24 which identifies the alignment mark 6 formed on a printed board 2, a lens 25 having an image pick-up area D, a half mirror 22 which is set at about 45 deg. against the optical axis E of the lens 25, a surface emitting illuminator 23 provided on the side face of the half mirror 25, a diffusing plate 26, etc. Therefore, the alignment mark recognizing accuracy of the camera device 24 is improved, because the light emitted from the illuminator 23 evenly irradiates the mark 6 on the board 2 through the half mirror 22, and the camera device 24 can take the picture of the mark 6 in a 'brightly shining state' even when the mark 6 has a specular surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device of a mounting machine for mounting electronic parts on a printed wiring board (hereinafter simply referred to as "printed board"), and more specifically,
The present invention relates to an illumination device for a mounting machine, which is an improved method for illuminating a printed circuit board in the mounting machine.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and thinning of various electronic devices, the mounting of electronic components used in these electronic devices on a printed circuit board has become more dense and the mounting intervals have become narrower. Along with this, automation of a mounting machine that mounts electronic components such as ICs on a printed circuit board is progressing, and mounting control of electronic components and confirmation of the mounting state are being performed by image processing. Under these circumstances, new efforts are needed to improve the mounting quality that is compatible with automation. The present invention relates to a lighting device of a mounting machine, which is being automated, and will be described below with reference to its configuration example.

An example of the configuration of a lighting device of a mounting machine in the prior art will be described with reference to FIG. FIG. 2 is a side view showing an example of a lighting device of a mounting machine according to the related art, and FIG.
It is a figure which shows the example which uses a light source, (b) is a figure which shows the example which uses an optical fiber light source, (c) is a figure which shows the example which uses a ring-shaped fluorescent lamp.

First, the structure and operation of a conventional lighting device for a mounting machine will be described with reference to an example using the LED light source shown in FIG. In FIG. 2A, reference numeral 1 indicates a lighting device of a mounting machine according to the related art. The illuminating device 1 of the mounting machine according to the related art described above includes an LED illuminator 3 for irradiating the printed circuit board 2 with light, and an LED illuminator 3 for irradiating the printed circuit board 2 mounted on an installation portion of the printed circuit board in the mounting machine. A camera device 4 for identifying a reference mark (alignment mark) formed on the printed circuit board 2 by receiving irradiation light, a solder land for mounting an electronic component, and the like, a lens 5 connected to the camera device 4, and the like. It is roughly configured.

Alignment marks 6 are formed on the surface of the printed circuit board 2 by gold plating or solder coating. In the camera device 4, the LED illumination 3 is used.
When the alignment mark 6 is detected by receiving the irradiation light of and the outer shape of the alignment mark 6 is recognized by image processing, the mounting position of the electronic component on the printed circuit board 2 is corrected with reference to it. In addition, as an example, solder lands for mounting chip-shaped electronic components are formed on the surface of the printed circuit board 2 in a square shape with copper foil having a film thickness of 35 μm so as to face each other in a planar shape, and in the periphery thereof. A solder resist layer is formed by opening the solder land portion. A wiring pattern for transmitting a signal extends to a predetermined portion of the solder land. A chip-shaped electronic component is mounted on the solder land by a mounting machine or the like, and then the chip-shaped electronic component is fixed to the printed circuit board 2 by melting a solder paste, for example.

FIG. 2B shows an example in which an optical fiber light source is used in a lighting device as a second example of the prior art, and the lighting device of the mounting machine of the second example of the prior art is the same as that of the prior art. 1
As shown in FIG. 2A showing an example, the printed circuit board 2 has alignment marks 6 formed thereon, a metal halide light source or halogen light source 7 as a lighting device, a ring light 8, a camera device 4, a lens 5, and the like. And
Light emitted from a metal halide light source, a halogen light source 7 or the like as an illuminating device is guided to a ring light 8 by using an optical fiber such as plastic or glass fiber, and the ring-shaped ring light 8 illuminates the printed circuit board 2. .

Further, FIG. 2C shows an example in which a ring-shaped fluorescent lamp is used as a lighting device as a third example of the conventional technique, and the lighting device of the mounting machine of the third example of the conventional technique is the same as that of the conventional technique. First
As shown in FIG. 2A showing an example, a printed circuit board 2 on which alignment marks 6 are formed, a ring-shaped fluorescent lamp 9 including a hot cathode lamp, a cold cathode lamp, etc. as an illuminating device, a camera device 4, a lens 5, etc. It is configured. Then, the printed circuit board 2 is illuminated with irradiation light from a ring-shaped fluorescent lamp 9 including a hot / cold cathode lamp as an illuminating device.

Next, the details of the illuminating device of the mounting machine in the prior art will be described with reference to FIGS. FIG. 3 is an enlarged view of an irradiation unit of a lighting device of a mounting machine of a conventional technology, FIG. 4 is a top view showing an image of an alignment mark on a printed circuit board in the lighting device of a mounting machine of the conventional technology, and FIG. It is a side view which shows the example of irradiation of the epi-illumination system which is an example of the illuminating device of the mounting machine of a prior art.

First, in the enlarged view of the irradiation portion of the illumination device of the conventional mounting machine of FIG. 3, for example, on the surface of the gold-plated alignment mark 10 formed on the printed circuit board 2 mounted on the conventional mounting machine. Further, it is assumed that the light from the light source 11 is emitted. Then, of the light reflected on the surface of the gold-plated alignment mark 10, the light A incident on the lens 5 is recognized as "shining brightly" because the gold-plated alignment mark 10 is a highly reflective film. On the other hand, of the light emitted from the light source 11, the light B which is not incident on the lens 5 is recognized as "dark" because the light is reflected light. An example of the alignment mark image is shown in FIG.

In FIG. 4, the image of the gold-plated alignment mark 10 formed on the printed circuit board 2 recognized by the camera device 4 is "dark" as shown, and "brightly shines" due to specular reflection. The part that is recognized as such is mixed and visualized like a void. In such a situation, the gold-plated alignment mark 1
The same applies to solder coats other than 0 and alignment marks that have been subjected to a predetermined process.

Further, FIG. 5 shows an example of a lighting device of a mounting machine according to the prior art, which is commonly referred to as an epi-illumination system, and the epi-illumination system is the same as the above-mentioned conventional example, the camera device 4, the lens 5, and the A half mirror 12 held at the tip of the lens 5 with an inclination angle of about 45 degrees with respect to the lens optical axis E.
Or the light source 11 disposed on the side surface of the half mirror 12.
And so on. The light emitted from the light source 11 is reflected by the emission surface of the half mirror 12 and irradiates the printed circuit board 2. The alignment mark 6 and the like on the printed circuit board 2 are recognized by the camera device 4 through the lens 5 by transmitting the reflected light of the irradiated light through the half mirror 12 in reverse. Note that the image recognition area in this epi-illumination method is small, and the light C deviated from the recognition area of the lens 5 is not recognized as a "brightly shining" image by the camera device 4, and a part thereof is "dark" as described above. "It is recognized like a void.

[0012]

However, in the illumination device of the mounting machine of the prior art described above, when the alignment mark formed on the printed circuit board is to be recognized by the camera device, the alignment mark is gold plated or solder coated. When the alignment mark is processed, the surface of the alignment mark is specularly reflected, so that the contrast for identifying the alignment mark depends on the reflection state, and the outer shape of the alignment mark is recognized by image processing. There was a problem that it would be difficult.

Further, in order to solve the above-mentioned inconvenience, if an explanation is given with reference to FIG. 5 of a lighting device of a mounting machine according to the prior art, a lighting method called a so-called epi-illumination system as shown in the drawing. However, this illumination method is similar to the above except that the recognition area of the alignment mark is narrow and the alignment mark is in the center of the imaging area, the surface of the alignment mark is mirror-reflected and the alignment mark There was a problem that it became difficult to identify.

The present invention has been made in consideration of the above points, and has improved the problem that the surface of the alignment mark formed on the printed circuit board is specularly reflected by the illumination light to make recognition difficult. Is to provide a lighting device.

[0015]

In order to solve such a problem, in a lighting device of a mounting machine of the present invention, a camera device for recognizing an alignment mark on a printed circuit board and about 45 degrees with respect to an optical axis of the camera device. A half mirror having an inclination equal to or larger than the image pickup area of the camera device, and an LED on the side surface of the half mirror.
A surface emitting type lighting device including an array and a diffusion plate, or a surface emitting type lighting device including a fluorescent lamp such as a cold cathode lamp and a light guide is provided. Then, the irradiation light of this illuminating device is reflected by the half mirror and is used as illumination of the printed circuit board, and the camera device has a predetermined imaging area through the half mirror to detect and recognize the printed circuit board. This has solved the above-mentioned problem.

[0016]

That is, in the illuminating device of the mounting machine of the present invention, since the alignment mark on the printed board is illuminated by providing the half mirror and the illuminating device which are larger than the image pickup area of the camera device, the alignment mark on the printed board is lit up. It is possible to illuminate evenly, and the camera device captures the entire alignment mark as a "brightly shining" image.
Stable image recognition can be performed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an illuminating device for a mounting machine according to the present invention will be described below with reference to FIG. FIG. 1 is a side view showing a main part of a lighting device of a mounting machine of the present invention. It should be noted that parts common to those described in the related art are designated by the same reference numerals, and description of their configurations and operations will be omitted.

In FIG. 1, reference numeral 21 indicates a lighting device of the mounting machine of the present invention. The illumination device 21 of the mounting machine of the present invention
Is a camera device 24 for identifying the alignment mark 6 and the like formed on the printed circuit board 2, a lens 25 having an imaging area D, and a lens optical axis E of the lens 25, as in the illumination device of the mounting machine of the related art. On the other hand, it is roughly configured by a large half mirror 22 arranged with an inclination of about 45 degrees, a surface emitting type lighting device 23 arranged perpendicularly to the reflection surface of the half mirror 22, and the like.

The illuminating device 23 is, for example, a chip type light emitting diode (Light Emitting Diode: hereinafter, simply referred to as “L”).
(Abbreviated as "ED") was used as an illumination light source by using an LED array in which a predetermined emission color of "ED" was arranged in a matrix. Further, in front of it, a diffuser plate 26 is provided to collect and uniformly irradiate the light.
It has a structure to arrange. Although not shown in the drawings, a light guide plate method can be given as another embodiment of the illumination device 23. In the light guide plate method, a light guide plate that has been subjected to a diffusion coating treatment that uniformly irradiates light by vapor deposition, silk printing, molding, etc. as a reflecting surface is arranged at one end of a fluorescent lamp light source composed of a heat / cold cathode lamp, etc. It is also possible to use a surface emitting type illumination light source. A diffuser plate is arranged in front of it for the same purpose as described above, and the light guide plate type illumination device can further increase the brightness.

The irradiation light emitted from the illumination device 23 is made uniform by the diffusion plate 26 and is incident on the half mirror 22. The irradiation light incident on the half mirror 22 is reflected by the reflecting surface of the half mirror 22 and irradiates the printed circuit board 2. At this time, the point of the present invention is that the irradiation area irradiated through the half mirror 22 is sufficiently wider than the imaging area D of the lens 25.

In this way, the light emitted through the half mirror 22 can evenly illuminate the alignment mark 6 formed on the printed board 2.
The reflected light in the image pickup area D that is reflected on the printed circuit board 2 passes through the half mirror 22 so that the lens 2
5, and is recognized by the camera device 24. As described above, according to the illuminating device of the mounting machine of the present invention, even the alignment mark 6 whose surface is specularly reflected can be taken into the camera device 24 as an image of “brightly shining”. Become. By image-processing the outer shape of the alignment mark 6 detected in this way, initialization of the mounting machine and automatic mounting of electronic components such as ICs on the printed circuit board can be stably performed.

The present invention is not limited to a particular mounting machine and can be applied to various mounting machines. For example, the present invention can be applied to an electronic component mounting machine using a rotary head system, an orthogonal or horizontal robot, and the function and form of the mounting machine are not limited in any way.

[0023]

As described above, according to the lighting device of the mounting machine of the present invention, the half mirror having a size larger than the image pickup area of the lens connected to the camera device is arranged,
By arranging a lighting device having a surface shape on the side surface of the half mirror and having a size larger than the image pickup area of the lens, even if the alignment mark has a specular reflection on the surface, the entire alignment mark becomes "bright". It is possible to capture the image in the camera device as an image in a “bright state”. Further, by performing image processing on the outer shape of the alignment mark detected in this way, it becomes possible to accurately perform image recognition of the alignment mark,
Automatic mounting of electronic components such as ICs on a printed circuit board can be stably performed, and mounting efficiency is improved. Further, since there is no restriction on the formation of the alignment mark and the alignment mark formed under any condition can be stably recognized, the manufacturing efficiency of the printed circuit board is improved.

[Brief description of drawings]

FIG. 1 is a side view showing a main part of a lighting device of a mounting machine of the present invention.

2A and 2B are side views showing an example of a lighting device of a mounting machine of a conventional technique, FIG. 2A is a diagram showing an example using an LED light source, and FIG. 2B is an example using an optical fiber light source. It is a figure and (c) is a figure showing an example using a ring-shaped fluorescent lamp.

FIG. 3 is an enlarged view of an irradiation unit of a lighting device of a mounting machine according to the related art.

FIG. 4 is a top view showing an image of an alignment mark on a printed board in a lighting device of a mounting machine of a conventional technique.

FIG. 5 is a side view showing an irradiation example of an epi-illumination system, which is an example of a lighting device of a mounting machine of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Illumination device for mounting machine of prior art 4, 24 Camera device 3 LED lighting 5, 25 Lens 6 Alignment mark 7 Halogen light source 8 Ring light 9 Ring fluorescent lamp 10 Gold-plated alignment mark 11 Light source 12, 22 Half mirror 21 Mounting of the present invention Lighting device 23 Lighting device 26 Diffusing plate A, B, C Light D Imaging area E Lens optical axis

Claims (5)

[Claims] 1. A lighting device for a mounting machine, which detects an alignment mark on a printed circuit board and controls the position thereof, the camera device detecting the alignment mark on the printed circuit board in a predetermined imaging area, and the camera device. A half mirror disposed so as to have an inclination of about 45 degrees with the optical axis of, and an illuminating device disposed on a side surface of the half mirror, and the light emitted from the illuminating device is reflected by the half mirror. An illumination device for a mounting machine, wherein the alignment mark is detected by the camera device via the half mirror as an illumination of the printed circuit board. 2. The illuminating device for a mounting machine according to claim 1, wherein the illuminating device is a surface emitting type illuminating device including an LED array and a diffusion plate. 3. The mounting apparatus lighting apparatus according to claim 1, wherein the lighting apparatus is a surface-emitting type lighting apparatus including a fluorescent lamp and a light guide. 4. The illuminating device for a mounting machine according to claim 1, wherein an area of the half mirror is equal to or larger than an imaging area of the camera device. 5. The mounting according to claim 1, wherein an area of the lighting device is equal to or larger than an area in which an imaging area of the camera device is reflected by the half mirror with the printed circuit board as a reflecting surface. Lighting equipment.