JP3644212B2 - Electronic component mounting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic component mounting equipment for mounting electronic components on a substrate.
[0002]
[Prior art]
In an electronic component mounting apparatus that mounts an electronic component on a substrate, a method of correcting a positional shift of the electronic component by image recognition is frequently used in order to improve mounting position accuracy. In this method, an electronic component is picked up from a parts feeder by a transfer head, the electronic component is recognized by a camera while the electronic component is held, a positional deviation is detected, and the electronic component is placed on the substrate by correcting the positional deviation. It is to be installed.
[0003]
As an illumination method for recognizing an electronic component by a camera, there is a conventional method in which illumination light is irradiated to a light diffusion plate provided behind the electronic component, and light diffusely reflected by the surface of the diffusion plate is incident on the camera. Generally used.
[0004]
[Problems to be solved by the invention]
However, in this method, only a part of the illumination light emitted from the illumination light source is incident on the camera, so the amount of illumination light is small, and it takes time until a sufficient amount of light enters the camera to recognize the electronic component. There was a problem.
[0005]
In addition, since there is a nozzle that adsorbs an electronic component between the light source and the light diffusion plate, there is a problem that a portion that becomes a shadow of the nozzle is generated, and the recognition accuracy decreases due to this shadow.
[0006]
Accordingly, the present invention aims at providing an electronic component mounting equipment for the recognition by the camera can be performed in a short time with high accuracy for the positional deviation correction of the electronic component.
[0007]
[Means for Solving the Problems]
The electronic component mounting apparatus according to claim 1 is a positioning unit that positions a substrate, a parts feeder that supplies the electronic components, a transfer head that picks up electronic components from the parts feeder and mounts them on the substrate, and the transfer A camera that is provided in a moving path of the electronic component held by the head and recognizes the electronic component, a nozzle that is provided in the transfer head and sucks the electronic component, and a reflection that is located behind the electronic component sucked by the nozzle A light source unit that irradiates light toward the reflection plate, and the reflection plate is divided into regions corresponding to the direction of the light source unit, and these regions are only illumination light from the light source unit in a specific direction. the has a reflective surface on the mirror that reflects be directed to the camera, the surface of the reflective surface is covered with a protective film, the protective film is a near-infrared transmission filter this near-infrared transmission Fi Ru consists of a hard coating agent coating that covers the surface of the data.
[0008]
An electronic component mounting apparatus according to a second aspect is the electronic component mounting apparatus according to the first aspect , wherein sawtooth-shaped steps are formed in a lattice pattern on the surface of the reflecting surface .
[0010]
According to the first aspect of the present invention, the reflector that is behind the electronic component and reflects the illumination light has a mirror-like reflection surface that reflects the illumination light from a specific direction toward the camera, and this By covering the surface of the reflective surface with a near-infrared transmission filter and a protective film made of a hard coating agent coating covering the surface of the near-infrared transmission filter, it is possible to illuminate electronic components with a sufficient amount of light and to protect the reflective surface be able to.
According to the second aspect of the present invention, the reflected light of the illumination light from the light source is directed toward the camera, and the electronic component P can be illuminated with a sufficient amount of light without diffusing the illumination light in a useless direction. it can.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a plan view of an electronic component mounting apparatus according to an embodiment of the present invention, FIG. 2 is a partial sectional view of the electronic component mounting apparatus, and FIG. 3A is a perspective view of a reflector of the electronic component mounting apparatus. 3B is a partial cross-sectional view of the reflection plate of the electronic component mounting apparatus, FIG. 4 is a partial cross-sectional view of the electronic component mounting apparatus, and FIG. 5 is a filter characteristic of the reflection plate of the electronic component mounting apparatus and the light of the light source. Graphs showing strength characteristics, FIGS. 6A and 6B are image diagrams of a camera of the electronic component mounting apparatus.
[0013]
First, the overall structure of the electronic component mounting apparatus will be described with reference to FIG. In FIG. 1, a conveyor 2 is arranged in the X direction at the center of a base 1. The conveyor 2 conveys and positions the substrate 3. Therefore, the conveyor 2 is a positioning portion for the substrate 3. A large number of parts feeders 4 are arranged in parallel on both sides of the conveyor 2. The parts feeder 4 stores and supplies electronic parts P.
[0014]
On the X-axis table 6, a transfer head 7 for the electronic component P is mounted. The X-axis table 6 is installed on two Y-axis tables 5 arranged in parallel on the left and right sides. Therefore, by driving the X-axis table 6 and the Y-axis table 5, the transfer head 7 moves in the horizontal direction, picks up the electronic component P from the parts feeder 4, and mounts it on the substrate 3. Further, an image recognition unit 8 for the electronic component P that recognizes the electronic component P is disposed in the movement path of the transfer head 7.
[0015]
Next, the transfer head 7 and the image recognition unit 8 will be described with reference to FIG. In FIG. 2, the transfer head 7 is provided with a plurality (only one is shown in FIG. 2) of θ axes 10. A nozzle 11 that vacuum-sucks the electronic component P is mounted on the θ axis 10, and the θ axis 10 and the nozzle 11 move up and down integrally by a vertical movement means (not shown). A reflecting plate 12 is attached to the upper end portion of the nozzle 11, and the reflecting plate 12 is positioned behind the electronic component P when the electronic component P is sucked by the nozzle 11. The reflecting plate 12 is a mirror-shaped reflecting surface formed by applying a stepped process to the surface of a substantially disc-shaped resin plate to form a reflecting surface, and performing a mirror surface treatment such as aluminum deposition on the reflecting surface. . The surface of the reflector 12 is covered with a near-infrared transmission filter 14 as a protective film 13 and a hard coating agent film 15. The hard coating agent coating 15 covers the surface of the near infrared transmission filter 14.
[0016]
The image recognition unit 8 is provided with a lens 20 and a camera 21. The camera 21 is connected to the image processing unit 22, and the image processing unit 22 processes the image data of the electronic component P recognized by the camera 21 and detects the displacement of the electronic component P. A light source unit is disposed above the periphery of the lens 20. The light source unit includes an infrared LED light source 23 that irradiates infrared light with a wavelength of 850 nm and a red LED light source 24 that emits red light with a wavelength of 690 nm, each of which is a reflection positioned above the image recognition unit 8. It arrange | positions so that illumination light may be irradiated with respect to the board 12 from diagonally downward.
[0017]
Next, the details of the reflecting surface of the reflecting plate 12 will be described with reference to FIG. As shown in FIG. 3 (a), sawtooth-shaped steps are formed in a lattice pattern on the surface of the reflecting plate 12, and both the A and B arrow shapes are as shown in FIG. 3 (b). It has become. When light is incident on the reflecting plate 12 from a specific direction (in the example of FIG. 3B, an oblique direction as indicated by an arrow a), the light is reflected from the reflecting surface formed in a lattice shape with respect to the incident light. Then, it is totally reflected by the mirror surface of the reflecting surface having a specific angle, and is reflected in the direction of the arrow b shown in FIG. 3B (in the direction of the camera 21 below in the electronic component mounting apparatus). By forming such a reflection surface on the reflection plate 12, the reflected light of the illumination light from the light source is directed toward the camera 21, and the electronic component P can be made with a sufficient amount of light without diffusing the illumination light in a useless direction. Can be illuminated.
[0018]
In addition, when processing a sawtooth-shaped step on the surface of the reflecting plate 12, as shown in FIGS. 3A and 3B, two center lines C1 and C2 that intersect at the center of the reflecting plate 12 (position of the nozzle 11) are shown. The direction of the saw blade is symmetric. That is, the reflecting surface of the reflecting plate 12 is divided into four regions A1, A2, A3, and A4 by the center lines C1 and C2. One region, for example A1, can direct illumination light from the light source unit in two specific directions (arrow d direction and arrow f direction) toward the camera 21 as shown in FIG. . Thus, by providing sawtooth-shaped steps in a lattice pattern and arranging the sawtooth directions symmetrically with respect to the center line, incident light from the four directions around the reflector 12 can be directed toward the camera 21. . In this way, by directing all the illumination light toward the lower camera 21, no shadow is generated due to the presence of the nozzle 11, and accordingly, recognition accuracy is not deteriorated due to the influence of the shadow.
[0019]
Next, the protective film 13 on the surface of the reflector 12 will be described with reference to FIG. As shown in FIG. 4, a near-infrared transmission filter 14 that also serves as a protective film 13 is attached to the reflection surface of the reflection plate 12, and an acrylic translucent curable resin is provided on the near-infrared transmission filter 14. 15 is applied. The protective film 13 has a function of protecting the surface of the reflecting plate 12 from contamination and wear, and enables a camera 21 to switch an image recognition mode by a filter function described below.
[0020]
Here, the transmission characteristics of the near-infrared transmission filter 13 and the light intensity characteristics of the infrared LED used for the light source 23 and the red LED used for the light source 24 will be described with reference to FIG. The horizontal axis of FIG. 5 indicates the wavelength of light, the vertical axis indicates the light transmittance for the graph F indicating the characteristics of the near-infrared transmission filter 13, and the graph IR indicating the characteristics of the infrared LED, For the graph R showing the characteristics of the red LED, the light intensity is shown. As shown in FIG. 5, the red LED has a light intensity peak near 690 nm, and the infrared LED has a light intensity peak near 850 nm. And the near-infrared transmission filter 13 has the transmission characteristic that the transmittance | permeability falls rapidly with respect to the light of a wavelength of 750 nm or less, as shown in the graph F. FIG.
[0021]
In FIG. 4, when the infrared LED of the light source 23 is caused to emit light, the irradiated infrared light is transmitted through the near-infrared transmission filter 14 and reflected downward by the reflecting surface of the reflecting plate 12 (see arrow h). 21 receives light. At this time, since the reflected light is blocked by the electronic component P in the portion where the electronic component P exists, the camera 21 obtains a screen in which the portion of the electronic component P is a dark image and the surrounding background portion is a bright image. Can do.
[0022]
When the red LED of the light source 24 emits light, the irradiated red light hardly passes through the near-infrared transmission filter 14, so that the irradiated red light does not reach the reflecting surface of the reflecting plate 12, and is therefore irradiated. Red light is not reflected by the reflector 12. In this case, of the red light irradiated on the electronic component P, the light incident on the lower surface of the lead Pa is reflected downward and incident on the camera 21, and has a large contrast with the diffusely reflected light from other portions. Because of the difference, the camera 21 can obtain an image in which the lead Pa of the electronic component P is a bright image and the other part is a dark image. By including a plurality of light sources that irradiate illumination light of different wavelengths in this way, and by providing a filter that selectively transmits only the illumination light of a specific wavelength among these illumination lights on the reflector, that is, the type of illumination light By switching the type of illumination light incident on the reflector having different reflection characteristics, the form of the image recognized by the electronic component by the camera can be switched to either a bright image or a dark image.
[0023]
Next, an electronic component mounting method will be described. First, in FIG. 1, the transfer head 7 is moved above the electronic component P of the parts feeder 4, and the electronic component P is sucked and picked up by the nozzle 11. Next, the transfer head holding the electronic component P at the lower end of the nozzle 11 moves on the path M1. When the transfer head 7 passes over the image recognition unit 8, the electronic component P is recognized by the camera 21.
[0024]
At this time, the form of an image in which the electronic component P is recognized by the camera is switched depending on the type of electronic component to be mounted. That is, when there is a portion that reflects light well, such as a metal lead Pa, on the lower surface of the electronic component P, and it is appropriate to use this portion as a reference for position recognition, the light source of the image recognition unit 8 24 is caused to emit light. As a result, the camera 21 can obtain a screen as shown in FIG. 6A in which the lead Pa of the electronic component 6 is represented as a bright image. When there are few portions that clearly reflect light on the lower surface of the electronic component, the light source 23 is caused to emit light. As a result, the camera 21 can obtain a screen in which the entire electronic component 6 is represented as a dark image, as shown in FIG.
[0025]
Next, based on these screens, the image processing unit 22 detects the displacement of the electronic component P, that is, the displacement in the X direction, the Y direction, and the θ direction. Thereafter, these positional deviations are corrected by the correction operation of the transfer head 7, and the electronic component P is mounted at the correct position on the substrate 3 in the correct posture.
[0026]
As described above, a plurality of mirror-like reflective surfaces that are located behind the electronic component and are divided into regions corresponding to the direction of the light source unit and reflect only the illumination light from the light source unit in a specific direction toward the camera. By switching the type of illumination light incident on the reflection plate whose surface is covered with a protective film including a filter that selectively transmits only illumination light of a specific wavelength, the electronic component can be The form of the image recognized by can be switched to either a bright image or a dark image, and more accurate recognition can be performed according to the type of the electronic component P.
[0027]
【The invention's effect】
According to the present invention, the reflection plate that is behind the electronic component and reflects the illumination light has the mirror-like reflection surface that reflects the illumination light from a specific direction toward the camera, and the surface of the reflection surface Is covered with a protective film consisting of a near-infrared transmission filter and a hard coating agent coating covering the surface of the near-infrared transmission filter, so that an electronic component can be illuminated with a sufficient amount of reflected light, Protects the reflective surface from fouling and wear and enables long-term use. By directing all of the illumination light downward, a shadow due to the presence of a nozzle that sucks the electronic component does not occur, and therefore, recognition accuracy does not deteriorate due to the influence of the shadow. In addition, it has a plurality of mirror-like reflective surfaces that are located behind the electronic component and are divided into regions corresponding to the direction of the light source unit and reflect only illumination light from the light source unit in a specific direction toward the camera. The electronic component is recognized by the camera by switching the type of illumination light incident on the reflection plate, which is a reflection plate that is covered with a protective film including a filter whose surface selectively transmits only illumination light of a specific wavelength. Since the image form can be switched to either a bright image or a dark image, appropriate position recognition according to the type of electronic component can be performed.
[Brief description of the drawings]
FIG. 1 is a plan view of an electronic component mounting apparatus according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view of an electronic component mounting apparatus according to an embodiment of the present invention. FIG. 4B is a partial cross-sectional view of the reflector of the electronic component mounting apparatus according to the embodiment of the present invention. FIG. 4 is an electronic component according to the embodiment of the present invention. FIG. 5 is a graph showing a filter characteristic of a reflector and a light intensity characteristic of a light source of an electronic component mounting apparatus according to an embodiment of the present invention. (B) Image diagram of camera of electronic component mounting apparatus according to an embodiment of the present invention
2 Conveyor 3 Substrate 4 Parts feeder 7 Transfer head 8 Image recognition unit 11 Nozzle 12 Reflector 13 Protective film 14 Near infrared transmission filter 21 Camera 22 Image processing unit P Electronic component

Claims (2)

A positioning unit for positioning the substrate, a parts feeder for supplying electronic components, a transfer head for picking up electronic components from the parts feeder and mounting them on the substrate, and a movement path of the electronic components held by the transfer head A camera provided for recognizing an electronic component, a nozzle provided in the transfer head for sucking the electronic component, a reflecting plate located behind the electronic component sucked by the nozzle, and light directed toward the reflecting plate The reflector is divided into regions corresponding to the direction of the light source unit, and these regions are mirror surfaces that reflect only illumination light from the light source unit in a specific direction toward the camera. It has a reflecting surface, and the surface of the reflective surface is covered with a protective film, or the protective film is hard coating agent coating covering the surface of the near-infrared transmission filter and the near-infrared transmission filter Electronic component mounting apparatus according to claim formed Rukoto. 2. The electronic component mounting apparatus according to claim 1 , wherein sawtooth-shaped steps are formed in a lattice pattern on the surface of the reflecting surface .

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