JP3632449B2 - Cream solder application state inspection device and application state inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention images the cream solder is a non-glossy surface that is coated on the electrode and the electrode on having a solder leveler glossy surface as the object, the cream solder coating condition inspection apparatus and to identify them by image processing The present invention relates to a coating state inspection method.
[0002]
[Prior art]
2. Description of the Related Art In the field of manufacturing electronic components and equipment, image recognition methods are widely used in which an object such as an electronic component or a substrate is imaged with a camera, and the image is recognized to identify the object or detect the position. Yes. As one of these objects, there is a board after solder printing performed prior to mounting electronic components. Here, the application state of the cream solder printed on the electrodes of the board is recognized by an image and the application state is reached. An inspection to determine pass / fail is performed.
[0003]
[Problems to be solved by the invention]
By the way, some electrodes on a substrate have a solder leveler in which a solder film is formed on the electrode surface for the purpose of improving the solder bonding property. When cream solder is applied to an electrode having such a solder leveler, the cream solder applied to the solder leveler is essentially the same material and has similar colors. It was difficult to pick up images and identify them by color. For this reason, when trying to discriminate between those having similar colors, there is no method other than discriminating only by the difference in brightness, and there is a problem that it is difficult to improve the recognition accuracy. .
[0004]
Accordingly, the present invention provides a cream solder application state inspection apparatus and application state inspection method capable of improving the recognition accuracy of cream solder that is a non-gloss surface applied to an electrode having a solder leveler that is a glossy surface. With the goal.
[0005]
[Means for Solving the Problems]
The cream solder application state inspection device according to claim 1 , an electrode having a solder leveler that is a glossy surface and a camera that images cream solder that is a non-glossy surface applied on the electrode as an object for image recognition, An image processing unit that performs image processing on image data acquired by the camera, and a first illumination unit and a second illumination unit that illuminate the object during imaging, and emits white light to the first illumination unit. A white light source part, an opening part through which the optical axis of the camera passes is provided at the top, a reflection part having a diffuse reflection surface on the inner surface, and white light is guided from the white light source part toward the inner surface of the reflection part A light source that emits colored light and a light that projects the colored light from the colored light source toward the solder leveler that is the glossy surface of the object. And a light section.
[0006]
The method for inspecting the application state of cream solder according to claim 2 is characterized in that an electrode having a solder level that is a glossy surface and a cream solder that is a non-glossy surface applied on the electrode are imaged by a camera as an object for image recognition. A cream solder application state inspection method for acquiring image data and performing image processing on the image data to identify a solder leveler that is the glossy surface , wherein the object is obtained by a first illumination unit including a white light source unit. And the second illuminating unit having a colored light source unit illuminates the solder leveler that is the glossy surface of the object, images the object by the camera, and the solder that is the glossy surface. by receiving the white light irregularly reflected light from the cream solder is a specular reflection light and the non-glossy surface of the colored light from the leveler, the cream solder and the solder leveler in the acquired image It was to be different.
[0007]
According to the invention described in each claim, the entire illumination object is illuminated by the first illumination unit equipped with the white light source, and the solder leveler that is the glossy surface of the object is illuminated by the second illumination unit equipped with the colored light source. By illuminating and picking up an image by receiving the specularly reflected light from the solder leveler , the cream solder and the solder leveler can be accurately identified.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view of an image recognition apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of an imaging unit of the image recognition apparatus, and FIGS. 3 and 4 are partial sectional views of the image recognition apparatus.
[0009]
First, the structure of the image recognition apparatus will be described with reference to FIG. In FIG. 1, a movable table 2 is disposed on a base 1, and a substrate holder 3 is placed on the movable table 2. The substrate holding unit 3 holds a substrate 5 on the surface of which an electrode 4 having a solder leveler that is a recognition target is provided. The solder leveler on the surface of the electrode 4 is a glossy surface that regularly reflects light, and cream solder 4a is applied to the surface of the solder leveler. By driving the movable table 2, the substrate 5 moves horizontally and is positioned. That is, the movable table 2 and the substrate holder 3 serve as positioning means for positioning the substrate 5.
[0010]
Conveyor units 6 and 7 are disposed on both sides of the substrate holding unit 3. The conveyor unit 6 carries the substrate 5 into the substrate holding unit 3, and the conveyor unit 7 carries out the inspected substrate 5 from the substrate holding unit 3. An imaging unit 10 is disposed above the substrate holding unit 3. Here, the imaging unit 10 will be described with reference to FIG. As shown in FIG. 2, the imaging unit 10 includes a color camera 11, an optical system 12 including a zoom lens, a first illumination unit 13, and a second illumination unit 14. The substrate 5 held and positioned by the substrate holder 3 is illuminated by the first illuminator 13 and the second illuminator 14 and is imaged by the color camera 11 via the optical system 12.
[0011]
Next, the 1st illumination part 13 is demonstrated. Inside the case 15, there is provided a substantially hemispherical reflecting portion 16 having an opening 16 a provided at the top. The inner surface (inner surface) of the reflecting portion 16 is subjected to white alumite treatment, and the surface of the reflecting portion 16 is a diffuse reflecting surface that diffusely reflects incident light. A plurality of fiber cables 17 as light projecting parts are uniformly arranged in an annular shape at the lower part of the reflecting part 16, and the end part 17 a of the fiber cable 17 prevents the light from directly hitting the substrate 5. It opens at an obliquely upward angle inside.
[0012]
A plurality of fiber cables 17 are bundled and connected to a connector 18, and a white light source unit 19 for generating white light such as a halogen lamp is connected to the connector 18. By driving the white light source unit 19, white light is projected from the end 17 a of the fiber cable 17 toward the inner surface of the reflection unit 16, and the projected white light is diffusely reflected by the diffuse reflection surface of the reflection unit 16. The lower substrate 5 is illuminated. The substrate 5 illuminated in this way is imaged by the color camera 11 through the opening 16a.
[0013]
A second illumination unit 14 is provided above the first illumination unit 13. The second illuminating unit 14 is positioned below the colored light source unit 20 and the optical system 12 made of LEDs that generate colored light (red light in the present embodiment), and the colored light emitted from the colored light source unit 20 is directed downward. A half mirror 21 for irradiation is provided. By driving the colored light source 20, the red light is reflected downward by the half mirror 21 and illuminates the substrate 5 through the opening 16. That is, the half mirror 21 is a light projecting unit that projects red light onto the substrate 5 including the glossy surface. The reflected light from the substrate 5 passes through the half mirror 21 and enters the upper color camera 11.
[0014]
That is, the color camera 11 captures the imaging condition in which the substrate 5 is illuminated by the white diffused reflected light of the first illumination unit 13 and the coaxial illumination of the red light from above by the second illumination unit 14. Imaging can be performed under two imaging conditions. The image data obtained in this way is subjected to image processing by the image processing unit 22, and the processing result is sent to the control unit 23. In addition, the control unit 23 controls the white light source unit 19 and the colored light source unit 20 to switch the illumination light according to the imaging target.
[0015]
This image recognition apparatus is configured as described above. Next, the operation will be described with reference to the drawings. First, in FIG. 1, a substrate 5 to be inspected is placed on the conveyor unit 6, and is carried onto and held on the substrate holding unit 3. Next, the movable table 2 is driven to position the substrate 5 with respect to the imaging unit 10.
[0016]
Thereafter, when the white light source unit 19 is driven, white light is projected from the end portions 17a of the plurality of fiber cables 17 toward the diagonally upper side of the reflecting unit 16 as shown in FIG. At this time, the white light from the end portion 17a travels while diffusing within a certain angle range, is reflected by the surface of the reflecting portion 16, and is further diffused. Here, the end portion 17a is uniformly and annularly disposed below the reflecting portion 16, white light is projected from the circumferential direction inside the reflecting portion 16, and the substrate 5 positioned below reflects Illuminated uniformly from each direction by the diffusely reflected light from the section 16. Therefore, the cream solder 4a on the electrode 4 of the substrate 5 is imaged as a gray image which is the original color of the solder by this uniform illumination light.
[0017]
Next, the red light source unit 20 is driven by the control unit 23 to illuminate the electrode 4 of the substrate 5 by coaxial illumination of red light. Then, the surface of the solder leveler having a small surface roughness and a glossy surface has a high degree of regular reflection of the illumination light, and this reflected light is incident on the color camera 11 and imaged. That is, the red color of the illumination light is detected on the surface of the solder leveler on the color image. On the other hand, since the surface of the cream solder 4a is not glossy and has a large surface roughness, the red illumination light is irregularly reflected and the reflected light incident on the color camera 11 is small. Accordingly, in the color image, red is hardly detected in portions other than the surface of the solder leveler, and the solder leveler on the surface of the electrode 4 where the red color is detected can be clearly distinguished from the cream solder 4a. In this way, by using colored light illumination, it is possible to distinguish the same color / similar color parts from each other using the glossiness of the object or the difference in surface roughness. .
[0018]
The present invention is not limited to the above-described embodiment, and the object is not limited to a substrate after solder printing, but may be any material having the same color / similar color but having a difference in surface roughness. The illumination method for the colored light is not limited to the coaxial illumination, and any illumination method may be used as long as it is incident on the glossy surface and causes regular reflection.
[0019]
【The invention's effect】
According to the present invention, the entire object is illuminated by the first illumination unit having the white light source , the solder leveler that is the glossy surface of the object is illuminated by the second illumination unit having the colored light source, and the solder Since the specular reflected light of the colored light from the leveler is received and imaged , the solder leveler that is the glossy surface of the object is accurately distinguished from the cream solder that is the non-glossy surface , and the material is the same color and similar Parts that are colors can be distinguished from each other.
[Brief description of the drawings]
FIG. 1 is a front view of an image recognition apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of an imaging unit of the image recognition apparatus according to an embodiment of the present invention. FIG. 4 is a partial cross-sectional view of an image recognition apparatus according to an embodiment of the present invention.
5 Substrate 10 Imaging unit 11 Color camera 13 First illumination unit 14 Second illumination unit 16 Reflection unit 17 Fiber cable 19 White light source unit 20 Colored light source unit 22 Image processing unit

Claims (2)

A camera that picks up an electrode having a solder level that is a glossy surface, and a cream solder that is a non-glossy surface applied on the electrode as an object for image recognition, and an image processing unit that performs image processing on image data acquired by the camera And a first illuminating unit and a second illuminating unit that illuminate the object at the time of imaging. The first illuminating unit includes a white light source that emits white light, and an optical axis of the camera on the top. The second illumination unit includes: a reflection unit provided with an opening through which has a diffuse reflection surface on the inner surface; and a light projecting unit that guides white light from the white light source unit and projects the light toward the inner surface of the reflection unit. a colored light source unit for emitting colored light, cream solder, characterized in that it comprises a light projecting portion for projecting light toward the colored light of the colored light source unit to the glossy surface and is solder leveler of the object Application state inspection device. An image having a gloss level solder leveler and a non-gloss surface cream solder coated on the electrode is imaged as an object for image recognition to obtain image data, and the image data is processed. A cream solder application state inspection method for identifying a solder leveler that is a glossy surface , wherein the entire object is illuminated by a first illumination unit having a white light source unit, and a colored light source unit is provided. by the object the camera in a state where it is illuminated solder leveler a glossy surface of the second illumination part imaging the object, a positive reflected light and non-glossy surface of the colored light from the a glossy surface solder leveler by receiving the diffusely reflected light of the white light from one cream solder, the cream solder coating condition test, characterized by identifying the cream solder and the solder leveler in the acquired image Method.

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