JP2010019600A - Substrate visual inspection method and substrate visual inspecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To generate an image having a matched relation between a color and a tilt angle, and to recognize the tilt state of a steep soldered surface which cannot be recognized through imaging from the right overhead direction. <P>SOLUTION: A camera 1 for color imaging is arranged over a dome-shaped illumination device 2, on which a plurality of light emitting parts capable of switching a luminescent color are arranged, and reflecting mirrors 31, 32 are arranged opposite to a direction which is orthogonal to a center line C of the illumination device 2; and each position of the mirrors 31, 32 is controlled, to thereby set either a direct-vision imaging mode or an oblique-vision imaging mode in the camera 1. In the illumination device 2 in the direct-vision imaging mode, each light emission domain of red, green and blue is generated, with boundaries between each domain uniform in all directions. Meanwhile, in the oblique-vision imaging mode, the luminescent color of each light-emitting part is controlled so that each color of red, green and blue in an image shows the same angle range as that in an image in the direct-vision imaging mode, and so that a steeper tilt angle is represented in purple. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention targets a component mounting board after soldering, performs imaging while irradiating a plurality of types of color light from directions with different incident angles, and uses each color pattern in the generated image to provide each of the colors on the board. The present invention relates to a method for inspecting the surface state of a soldering site, and a board appearance inspection apparatus used for this type of inspection.

  The applicant has developed a large number of board appearance inspection apparatuses each including an illumination device that irradiates three types of color light of red, green, and blue from directions having different incident angles, and a two-dimensional color camera. This inspection apparatus generates an image in which the inclination state of the fillet on the substrate is represented by a distribution pattern of a plurality of color regions by the above-described illumination device and camera (see Patent Document 1).

  The inspection apparatus described in Patent Document 1 performs illumination with each color light using three ring-shaped light sources having different diameters, but in recent years, a dome in which a large number of LEDs are arranged on the inner surface. Increasing cases use mold-type lighting devices. In this case, as shown in FIG. 13, the illumination device 2 having the peephole 23 in the center is arranged above the substrate S, the camera 1 is placed above the illuminating device 2, and the optical axis is set to the center line C of the peephole 23. Arrange them together. Further, the light emission colors of the respective LEDs are controlled over the entire circumference so that red, green, and blue light emission regions are sequentially generated from the center of the illumination device 2 toward the lower edge.

  In Patent Document 2, an optical unit including a pair of reflecting mirrors is arranged inside the dome-shaped lighting device as described above, and the position of each reflecting mirror is changed, so that the optical axis of the imaging device is mounted on the substrate. It is described that the control for setting in the direct viewing direction and the control for setting the optical axis of the imaging device in the direction in which the substrate is imaged obliquely are executed by switching.

Japanese Patent Publication No.6-1173 Japanese Patent No. 3433739

  In the optical system described in Patent Document 1, it is necessary to ensure a certain distance between the lighting device and the substrate so that the lower end surface of the lighting device does not touch the components on the substrate. For this reason, the range of the incident angle of the illumination light with respect to a board | substrate is limited, and the angle range of the inclined surface which can reflect an illumination color in an image will also be limited in connection with it.

  For example, in the illuminating device 2 of the example of FIG. Therefore, the inclined surface that can receive blue light from the lowermost end portion and regularly reflect it in the direction (directly upward direction) incident on the camera 1 is the steepest surface that can be detected by this optical system. According to the configuration of the optical system, the angle of the inclined surface is 37.5 degrees (see FIG. 14). Therefore, it is considered that an image reflecting the illumination color cannot be obtained with a fillet that is steeper than 37.5 degrees because regular reflection light cannot be incident on the camera 1 even when light is irradiated.

  On the other hand, according to the invention described in Patent Document 2, by changing the direction of the optical axis of the camera from the vertical direction to the oblique direction, even specularly reflected light from a surface with a steep inclination angle is incident on the camera. The angle range that can be expressed by colors can be expanded. However, in this method, as the angle difference between the orientation in which the fillet gradient is generated and the orientation of the camera increases, the relationship between the color of the specularly reflected light incident on the imaging device and the inclination angle changes. It becomes difficult to match the relationship between the color in the image and the tilt angle. Therefore, it becomes a state which cannot discriminate | determine the inclination state of a fillet based on a fixed reference | standard.

  The present invention pays attention to the above-mentioned problem, and even when the substrate is imaged obliquely from above, an angle that can generate an image in which the relationship between the color and the inclination angle is matched and can be recognized by an image captured from directly above It is an object to be able to generate an image reflecting an illumination color even on a surface with a steeper angle than the range, and to improve the accuracy of discrimination with respect to the inclined state of the solder surface.

  The substrate appearance inspection method to which the present invention is applied is for inspecting a substrate on which a plurality of types of components are soldered, and the incident angle increases as the distance from the center of the light emitting portion capable of switching the emission color increases. A plurality of illuminating devices that are arranged over the entire circumference are arranged above the substrate with the center line aligned in the vertical direction. In addition, an image pickup apparatus for color photographing is arranged so as to pick up an image of the substrate from obliquely above.

  Further, in this method, the emission color of each light emitting unit is controlled so that a plurality of groups having different emission colors are generated in accordance with the change in the incident angle in the arrangement of the light emitting units in each direction of the illumination device, and under the illumination by the control. Using the color pattern in the image generated by the imaging at, the suitability of the surface state of the soldered part included in the field of view of the imaging device is inspected.

  In the above, each “light emitting portion” corresponds to one local region in the light emitting surface of the illumination device. Each light emitting unit includes at least one light emitter (such as an LED) capable of switching the light emission color in accordance with an external control signal.

  In the first method for solving the above-described problem, an angle steeper than the above range is within the range of the inclination angle of the inclined surface that can regularly reflect the light from the illumination device in the direction along the center line of the illumination device. An angle range having a continuous range is divided into a plurality of ranges, and different colors are associated with the plurality of angle ranges generated by the division. Next, for each light emitting unit of the lighting device, the illumination light from the light emitting unit can be specularly reflected in the direction incident on the imaging device based on the illumination direction of the light emitting unit with respect to the substrate and the imaging direction of the imaging device. An inclination angle of the inclined surface is specified, and a color corresponding to an angle range including the specified inclination angle is determined as a light emission color of the light emitting unit among a plurality of angle ranges generated by the division.

  Then, each light emitting unit is controlled to turn on the determined emission color, and an image for inspection is generated by driving the imaging device under illumination by this control.

  Assuming that light from a specific light emitting unit in the illuminating device is applied to a certain solder slant line and specularly reflected, and this specularly reflected light is incident on the imaging device, the illumination direction of the above light emitting unit and imaging The inclination angle of the inclination line where the above-described regular reflection occurs can be obtained based on the opening of the azimuth between the imaging direction of the apparatus and the relationship of the elevation angle with respect to the substrate. The above method pays attention to this point, and on the premise that the correspondence between the color in the image and the inclination angle is always constant, the illumination light from the light emitting unit is incident on the imaging device for each light emitting unit. The inclination angle of the inclined surface that can be regularly reflected in the direction is specified, and control is performed so that the light emitting region emits light with a color corresponding to the specified angle.

  According to the above method, as long as the specularly reflected light can be incident on the imaging device, the same color can be used as long as the inclination angle is the same regardless of the orientation of the inclined surface of the solder. This makes it possible to generate an image representing an inclined surface.

  Furthermore, in the above method, for a range in which an angular range that is steeper than the above range is continuous with an angular range that can generate an image with a color corresponding to the illumination color when imaging the substrate from directly above, This range is divided into a plurality of portions so that the inclined surfaces corresponding to the divided angle ranges are expressed in different colors. Therefore, it is possible to generate an image reflecting the illumination color even on a surface with an inclination angle steeper than that which can be recognized when imaging the substrate from directly above, and to correctly recognize the inclination state of the steep surface. It becomes possible.

  In the second board appearance inspection method according to the present invention, an illumination device having the same configuration as described above is disposed above a component mounting board with the center line aligned in the vertical direction, and color imaging is performed above the same board. The image pickup device is disposed so as to be switchable between a direct-viewing imaging state in which the substrate is imaged from a direction along the center line of the lighting device and a perspective imaging state in which the substrate is imaged obliquely from above. In addition, the imaging device is set to a direct-view imaging state or a perspective imaging state according to the part to be inspected on the substrate, and a plurality of emission colors differ depending on the change in incident angle in the array of light emitting units in each direction of the illumination device The surface of each soldering part included in the field of view of the imaging device is controlled using the color pattern in the image generated by imaging under illumination by controlling the emission color of each light emitting unit so that a group of Determine the suitability of the condition.

  Furthermore, in the above method, when the imaging device is set to the direct-viewing imaging state, the emission color of each light-emitting area in the direct-viewing imaging state so that the boundary position between the groups of the light emitting units of the illumination device is uniform over the entire circumference. To decide.

  In addition, the correspondence between the color in the image and the inclination angle is the same as in the direct-viewing imaging state for the inclined surface represented by the color corresponding to each light emission color of the lighting device in the image captured in the direct-viewing imaging state. In addition, the correspondence between the color in the image obtained by the imaging under the perspective imaging state and the inclination angle so that the color that did not appear in the image under the direct vision imaging state corresponds to at least one angle range corresponding to the steeper surface. For each light emitting unit, the illumination light from the light emitting unit is incident on the imaging device under the perspective imaging state based on the illumination direction with respect to the substrate of the light emitting unit and the imaging direction of the imaging device under the perspective imaging state. By specifying the inclination angle of the inclined surface that can be regularly reflected in the direction, and setting the color corresponding to the angle range including the specified inclination angle as the emission color of the light emitting region, the perspective view Determining the light emission color of each light emitting unit under the image conditions.

  Further, in the above method, each light emitting unit of the illumination device is controlled to turn on the emission color based on the determination according to the imaging state of the imaging device, and the imaging device is driven under illumination by each light emitting unit. Thus, an image for inspection is generated.

According to the above method, the correspondence relationship between the color in the image and the inclination angle can be made constant regardless of whether the imaging apparatus is set to the direct-view imaging state or the perspective imaging state. Therefore, even if the imaging state is switched, the same reference can be applied to the recognition of the inclination angle based on the color.
Further, according to the above method, when the perspective imaging state is set, an angle range that is steeper than the range of the tilt angle that can be recognized under the direct vision imaging state is represented by a color that does not appear in the image under the direct vision imaging state. Images can be generated. Therefore, when the perspective imaging state is set, a steeply inclined surface can be easily and accurately recognized based on colors that do not appear in the image under the direct-viewing imaging state.

  Next, a substrate appearance inspection apparatus for carrying out the first substrate appearance inspection method described above includes an illumination device, an imaging device for color imaging, a reflection mirror, an imaging direction control unit, an illumination control unit, and a determination process. Means.

  The illuminating device has a plurality of light emitting portions that can switch the emission color over the entire circumference of the lens body having a peephole in the center, in a range from the peephole to the lower end edge of the housing, and the center line of the peephole Are arranged above the substrate to be inspected in a state in which is aligned in the vertical direction. In addition, the imaging device is provided above the substrate to be inspected, with the optical axis aligned with the center line of the peephole, and the pair of reflecting mirrors can be changed in height or inclination in the housing of the lighting device. Are arranged so as to face each other along a direction orthogonal to the center line of the peephole.

  The imaging direction means sets the height or inclination of each reflecting mirror according to the part to be inspected on the substrate while maintaining one position of each reflecting mirror on the center line of the peephole, thereby capturing the image of the imaging device. Control the direction. The illumination control unit controls the emission color of each light emitting unit so that a plurality of groups having different emission colors are generated in accordance with the change in the incident angle in the arrangement of the light emitting units in each direction of the illumination device, and the discrimination processing unit is The image generated by the imaging device is input under the control of the imaging direction control means and the illumination control means, and the suitability of the surface condition of the soldering part included in the field of view of the imaging device is determined using the color pattern in the input image To do.

  Further, the illumination control means includes an angle range in which an angle range that is steeper than the above range is continued in an inclination angle range of an inclined surface that can regularly reflect light from the illumination device in a direction along the center line of the illumination device. The relationship table in which different colors are associated with a plurality of angle ranges set by dividing the target angle range, and the lighting direction of the light emitting unit with respect to the substrate, Based on the imaging direction of the imaging device, identify the inclination angle of the inclined surface that can regularly reflect the illumination light from the light emitting unit in the direction of incidence on the imaging device, and collate the above relation table with the specified inclination angle Thus, there is provided a light emission color determining means for executing the process of determining the light emission color of the light emitting section for each image pickup direction set by the image pickup control means. And according to the imaging direction of an imaging device, the emission color of each light emission part is controlled based on the determination of the emission color determination means with respect to the imaging direction.

  According to the apparatus having the above configuration, for each soldering site to be inspected, it is possible to select an imaging direction suitable for imaging according to the inclination angle and surrounding conditions, and in any imaging direction, the color in the image can be selected. It is possible to generate an image in which the relationship with the inclination angle is consistent, and to perform inspection based on the same reference.

  Next, a substrate appearance inspection apparatus for carrying out the second substrate appearance inspection method includes a lighting device and an imaging device having the same configuration as described above, and a direction orthogonal to the center line of the peephole in the housing of the lighting device. And a pair of reflecting mirrors supported so as to be capable of reciprocating along the facing direction.

Further, the board appearance inspection apparatus includes the following imaging control means, illumination control means, and discrimination processing means.
The imaging control means stops the reflecting mirrors in such a manner that the reflecting mirrors are stopped in a state of being opposed to each other with the center line of the peephole interposed therebetween, and the one reflecting mirror is positioned on the center line. The imaging state of the imaging device is switched by switching and executing the second positioning in accordance with the part to be inspected on the substrate. The illumination control unit controls the light emission color of each light emitting unit so that a plurality of groups having different light emission colors are generated in the arrangement of the light emitting units in each direction of the illumination device according to the change in the incident angle.

  The discrimination processing unit inputs an image generated by the imaging device under the control of the imaging control unit and the illumination control unit, and uses the color pattern in the input image, and the surface of the soldering part included in the field of view of the imaging device Determine the suitability of the condition.

  The illumination control means is set to a direct-view imaging state in which the imaging means images the substrate from the direction along the center line of the peephole by the first positioning as a setting table indicating the relationship between each light emitting unit and the emission color. And a setting table used when the imaging device is set in a perspective imaging state in which the imaging device images the substrate from diagonally upward by the second positioning, respectively. . The illumination control unit controls the emission color of each light emitting area with reference to a setting table corresponding to the imaging state set in the imaging apparatus.

  Regarding the above setting table, in the setting table used when setting the direct-view imaging state, the emission color of each light emitting region is registered so that the boundary position between the groups of the light emitting units of the illumination device is uniform over the entire circumference. .

  On the other hand, in the setting table used at the time of setting the perspective imaging state, the color and the inclination angle in the image of the inclined surface represented by the color corresponding to each light emission color of the lighting device in the image captured under the direct-viewing imaging state So that the color that did not appear in the image under the direct-viewing imaging state corresponds to at least one angle range corresponding to the steeper surface. Illumination from the light emitting unit is determined based on the illumination direction with respect to the substrate of the light emitting unit and the imaging direction of the imaging device for each light emitting unit, by determining the correspondence between the color in the image captured under the perspective imaging state and the inclination angle. A color corresponding to an angle range including the specified tilt angle by specifying the tilt angle of the tilted surface capable of specularly reflecting light in the direction in which the light is incident on the imaging device under the perspective imaging state By determining the emission color of the light-emitting portion, the emission color of each light emitting portion defined is registered.

  According to the apparatus having the above-described configuration, the imaging apparatus is set to either the direct-view imaging state or the perspective imaging state in accordance with the soldered part to be inspected, and the color in the image is obtained in any imaging. It is possible to carry out an inspection based on the same reference with a constant correspondence between the angle and the inclination angle. Furthermore, in the inspection based on the perspective imaging state, it is possible to detect the steep inclined surface based on the color that does not appear in the image in the direct-viewing imaging state, and to accurately determine the inclined state of the soldered portion.

  In a preferable aspect of the above-described substrate appearance inspection apparatus, each reflection mirror is supported so that the height or inclination of each reflection mirror can be changed while maintaining a relationship of facing each other along a direction orthogonal to the center of the illumination apparatus. The imaging control unit sets the imaging direction of the imaging apparatus to one of a plurality of directions by changing the height or inclination of each reflecting mirror when performing the second positioning with respect to the reflecting mirror. .

  Furthermore, a setting table is individually registered in the registration unit of the illumination control unit for each of a plurality of imaging directions in the perspective imaging state. The illumination control unit changes the illumination pattern of each light emitting unit using the setting table corresponding to the switched imaging direction each time the imaging direction of the imaging device in the perspective imaging state is switched by the imaging control unit.

  According to the above apparatus, the illumination pattern by the illumination apparatus is also set by selecting and setting the optimum one from a plurality of imaging directions according to the direction of the inclined line of the solder surface to be inspected. It is switched to a suitable one, and imaging can be performed under the setting state. Therefore, even when perspective imaging is performed from any imaging direction, the color in the image and the tilt angle can be matched.

  According to the above-described substrate appearance inspection method and substrate appearance inspection device, even when the substrate is imaged from a direction that intersects obliquely with respect to the center line of the illumination device, an image in which the relationship between various colors and the range of the inclination angle is matched In addition, an image reflecting the illumination color can be generated on an inclined surface that cannot be recognized when the substrate is imaged from directly above. Therefore, it is possible to accurately recognize a wider angle range than the conventional standard based on a unified standard, and to increase the accuracy of the inspection on the solder surface.

FIG. 1 is a block diagram showing an electrical configuration of the board appearance inspection apparatus.
This board appearance inspection apparatus (hereinafter simply referred to as “inspection apparatus”) is for inspecting the surface condition of a fillet generated between a land of the board and each component on the board after soldering. , Camera 1, illumination device 2, mirror unit 3, X stage unit 4, Y stage unit 5, control processing device 6, and the like. Although not shown, a substrate support table is provided to support the substrate to be inspected.

  The camera 1 and the illumination device 2 are arranged with a relationship as shown in FIG. The mirror unit 3 is for switching the direction of the optical axis of the camera 1.

  The X stage unit 4 supports the camera 1, the illumination device 2, and the mirror unit 3 above the substrate support table, and the Y stage unit 5 supports the substrate support table. In any of the stage portions 4 and 5, the support target can be moved along one axis. The direction of movement by one stage unit is orthogonal to the direction of movement by the other stage unit.

  The control processing device 6 includes a computer control unit 60, an image input unit 61, an imaging control unit 62, an illumination control unit 63, a mirror unit control unit 64, an X stage drive unit 65, a Y stage drive unit 66, an input unit 67, The display unit 68, the communication interface 69, and the like are connected.

  The image input unit 61 includes an interface circuit that receives R, G, and B image signals output from the camera 1 and an A / D conversion circuit that digitally converts these image signals. The imaging control unit 62 controls the imaging timing of the camera 1, and the illumination control unit 63 controls the lighting operation of each light emitting unit 21 in the lighting device 2 to be described later. The mirror unit control unit 64 controls the drive system in the mirror unit 3 to adjust the position, azimuth, and tilt of reflecting mirrors 31 and 32 described later.

  The input unit 67 is for performing a setting operation at the time of teaching, and includes a keyboard and a mouse. The display unit 68 is for displaying an image for inspection, an inspection result, and the like, and is configured by a liquid crystal panel or the like. The communication interface 69 is used for the purpose of transmitting the inspection result to an external device.

  In the above configuration, the movement amount of the X and Y stages necessary for aligning the camera 1 and the illumination device 2 with the substrate to be inspected is registered in the memory in the control unit 60. Also, as inspection data for fillet inspection, for each component on the board, in order to determine the suitability of inspection area setting data, a binary threshold value for detecting various color areas, and the area of the detected color area Is registered. In addition, for each component that is a target of the perspective imaging mode described later, information indicating the imaging direction of the camera 1 at the time of imaging is registered in association with identification information of the component. These pieces of registration information are set based on images of non-defective substrates and user setting operations in teaching prior to inspection.

  Furthermore, the memory stores control data indicating the control contents for the mirror unit 3 and a setting table in which information for illumination control for the illumination device 2 is registered. These contents will be described later in detail.

FIG. 2 shows the configuration of the optical system of the inspection apparatus together with the principle of inspection.
The illumination device 2 of this embodiment has a configuration in which a large number of light emitters are arranged concentrically on the inner surface of a dome-shaped housing 22. A viewing hole 23 of the camera 1 is formed at the zenith portion of the housing 21, and the camera 1 has the optical axis above the viewing hole 23 and the center line C of the viewing hole 23 (the center of the viewing hole 23 is vertical). It is a virtual line that passes along the direction.) The angle formed by the light from the lowermost end of the illumination device 2 with respect to the substrate S is 15 degrees as in the conventional example of FIG.

  The mirror unit 3 includes a case body 30 in which a pair of reflecting mirrors 31 and 32 is accommodated as a main body. The reflecting mirrors 31 and 32 are disposed in the case body 30 so as to face each other along the horizontal direction.

  Window portions (not shown) for allowing the reflected light to pass through are respectively provided on the upper surface and the lower surface of the case body 30. Further, the case body 30 can be rotated about the direction along the center line C of the lighting device 2 as an axis by a rotation mechanism, a horizontal movement mechanism, and a vertical movement mechanism (not shown), and can be moved in the horizontal direction and the vertical direction. Supported. Further, a tilt adjusting motor (not shown) is pivotally supported on each of the reflection mirrors 31 and 32.

  Note that the rotation mechanism and the horizontal movement mechanism have the same configuration as that of the drive mechanism 33 described in Patent Document 2. The vertical movement mechanism is configured by a slide rail, a driving motor, or the like.

  Next, in the illuminating device 2 of this Example, the multicolor light emission type LED chip 21 containing each light emitting element of red, green, and blue is used as a light-emitting body. These LED chips 21 are arranged concentrically so as to surround the viewing hole 23, but on the circuit, they are divided into four groups 20 as shown in FIG. It is wired so that a control signal is given. Hereinafter, the group 20 of the four LED chips 21 is referred to as “light emitting unit 20”. The LED chips 21 in each light emitting unit 20 are arranged in a square shape or in a line with the same height or the same direction.

  According to the circuit configuration of FIG. 3, the emission color of the illumination device 2 is controlled in units of the light emitting unit 20. However, if wiring is possible, an independent signal may be given to each LED chip 21 to control the emission color in units of LED chips 21.

  Further, the illumination device 2 is not limited to a dome-shaped device, and the incident angle of each LED chip 21 increases as the distance from the peep hole 23 increases around the peep hole 23 of the camera 1. It only has to be arranged. An optical member such as a Fresnel lens may be used to change the incident angle.

2, in this embodiment, for each component on the substrate S, one of the two imaging methods shown in (A) and (B) is selected, and imaging is performed. In the method (A), the light reflected from the substrate S in the direction along the center line C is determined by positioning the mirror unit 3 so that the reflecting mirrors 31 and 32 face each other with the center line C of the illumination device 2 interposed therebetween. Is guided to the camera 1. According to this method, as in the conventional example of FIG. 13, the camera 1 images the substrate S from directly above. Hereinafter, this imaging state is referred to as “direct-view imaging mode”.

  On the other hand, in the method of FIG. 2 (B), by adjusting the position of the mirror unit so that one reflection mirror 31 is located on the center line C of the illuminating device 2, the reflected light from the substrate S The light incident on the mirror 32 farther from the center line C is guided from the mirror 32 to the camera 1 via the mirror 31. That is, although the actual position and orientation of the camera 1 are not changed, the substantial imaging direction is changed from the vertical direction to the oblique direction, and the imaging state is the same as when the substrate is imaged obliquely from above. Hereinafter, this imaging state is referred to as “perspective imaging mode”.

  In the direct-view imaging mode, the illuminating device 2 controls the light emission color of each light emitting unit 20 so that the boundary position between the light emission regions of each color light of red, green, and blue is uniform over the entire circumference of the housing 22. . Thereby, in the direct-view imaging mode, the same state as the conventional example shown in FIG. 13 is set for illumination.

  On the other hand, in the illumination device 2 in the perspective imaging mode, in addition to red, green, and blue, a purple light emitting region is generated, and as shown in FIG. 4, the boundary position of each light emitting region is different depending on the orientation. The emission color of each light emitting unit 20 is controlled. Specifically, the slopes represented by the colors red, green, and blue in the image obtained by the direct-view imaging mode are represented by the same color in the image obtained by the perspective imaging mode, so that the slope is steeper. Make sure the surface is colored purple.

FIG. 5 shows the relationship between the four types of colors appearing in the image and the inclination angle θ of the fillet represented by each color.
In this embodiment, of the angle range (from 2.5 degrees to 37.5 degrees) in which the specular reflection light image can be generated in the direct-view imaging mode, the range from 2.5 degrees to 15 degrees is red. The range from 15 degrees to 25 degrees is represented in green, and the range from 25 degrees to 37.5 degrees is represented in blue. Furthermore, an inclined surface with an angle of 37.5 degrees or more, which is difficult to generate a regular reflection light image in the direct-view imaging mode, is expressed in purple. In FIG. 5, the angle range represented by purple is 37.5 degrees to 90 degrees, but the actual upper limit varies depending on the imaging direction of the camera 1 changed by the mirror unit 3. .

  FIG. 6 shows two examples of imaging in the perspective imaging mode. In each example, the upper part shows the relationship between the color of the specularly reflected light incident on the camera 1 and the inclined surface of the fillet, and the lower part shows the color distribution state in the image generated by the specularly reflected light. . Here, for convenience of comparison, the upper and lower stages indicate parts 100 and fillets 101.

  The fillet 101 in the example of FIG. 6A includes planes with inclination angles corresponding to the colors red, green, and blue, but is steeper than the angle range corresponding to blue at a location close to the component 100. There is an inclined surface. Further, in the fillet 101 in the example of FIG. 6 (2), although there is a surface with an inclination angle corresponding to blue at the lower end, the surface with an inclination angle corresponding to red or green is not included, and most of the surface is blue. However, it has a steep slope that cannot be expressed. According to the direct-view imaging mode, these steeply inclined surfaces become dark regions, so it is difficult to determine whether or not the inclined state is appropriate. Since it is expressed in purple, it is possible to accurately determine whether the inclined state is appropriate.

  On the other hand, in the perspective imaging mode, even if the relationship between the camera 1 and the illuminating device 2 and the substrate is adjusted so that the part to be inspected is included in the field of view of the camera 1, it depends on the position of each fillet and the direction of the gradient. Since it is necessary to switch the imaging direction, there is a disadvantage that the processing time becomes long. For example, in the case of inspecting a chip component in the example of FIG. 2 (B), after the regular reflected light from the right fillet is incident on the camera 1 in the state shown in FIG. It is necessary to rotate the mirror unit 180 ° so that the regular reflected light enters the camera 1 and image again.

  In consideration of the above points, in this embodiment, a fillet having an inclination angle exceeding 37.5 degrees, or a fillet that is difficult to confirm from directly above (for example, a J lead (a lead having a tip curved inward)) ), The inspection is performed in the perspective imaging mode by limiting the target to a part where it is difficult to reflect the illumination color in the image in the direct imaging mode, and the direct imaging is performed for other parts. We are going to perform inspection by mode. For parts to which the perspective imaging mode is applied, a plurality of imaging directions are determined according to the position and orientation of the fillet.

Next, parameters representing the imaging direction of the camera 1 and the illumination direction from the light emitting unit 20 will be described with reference to FIG.
(1) of FIG. 7 is a schematic perspective view (1) showing the relationship between the substrate S, the camera 1, and the illumination device 2, and (2) is a schematic view of the illumination device 2 as viewed from above. In the figure, point O is the intersection of the center line C of the illumination device 2 and the upper surface of the substrate S (hereinafter referred to as “substrate surface”), the point P is one point in the illumination device 2, and the point Q is the imaging direction. The positions of the reflecting mirrors 32 that determine the values are respectively shown.

  In this embodiment, the direction from point P to point O is the direction of illumination from point P, and this direction is shown as elevation angle A (shown in FIG. 7 (1)) and azimuth angle B (shown in FIG. 7 (2)). .) Here, the elevation angle A is an angle formed by a straight line passing through the points P and O with respect to the substrate surface. The azimuth angle B is an angle formed by the above straight line with respect to the straight line m directed from the center line C to the right.

  The imaging direction in the perspective imaging mode is a direction from the point Q to the point O, and is represented by an elevation angle α and an azimuth angle β. The elevation angle α is an angle formed by a straight line passing through the points Q and O with respect to the substrate surface, and the azimuth angle β is an angle formed by the above straight line with respect to the straight line m.

FIG. 8 shows an example of components to which the perspective shooting mode is applied.
The component 100 in this example is a chip component in which the fillets 101a and 101b are steeply inclined. When targeting such a component 100, it is necessary to individually determine the imaging direction for each of the fillets 101a and 101b at both ends. Also, with respect to the fillet 101a on the right side in the figure, since there is another tall component 102 in the vicinity, the imaging direction is such that the specularly reflected light that travels unobstructed by this component 102 is incident on the camera 1. It is necessary to consider the value of the elevation angle α.

FIG. 9 shows a method for changing the imaging direction in the perspective imaging mode.
First, in order to change the elevation angle α in the imaging direction, the height of the mirror unit 3 and the inclination of the reflecting mirrors 31 and 32 are changed as shown in FIG. In order to change the azimuth angle β, as shown in FIG. 9B, the mirror unit 3 is axially rotated to change the azimuth of each reflecting mirror in the facing direction.

  In the inspection apparatus of this embodiment, a plurality of combinations of the elevation angle α and the azimuth angle β are set as the imaging directions for the perspective imaging mode, and the light emission of each light emitting unit 20 of the illumination device 2 for each of these combinations. A setting table that defines colors is registered.

  For the setting of the imaging direction, for each combination of α and β, control data for determining the position and inclination of each reflecting mirror is determined so that the direction of the combination becomes the imaging direction, and this is registered in the memory of the control unit 60. Is done. The control data in this case indicates the amount of movement of the vertical movement mechanism, the rotation angle of the rotation mechanism, the rotation angle of the motor for adjusting the inclination of the reflection mirrors 31 and 32, and the like.

  The setting table for controlling the light emission color of each light emitting unit 20 is created in advance by determining the light emission color of each light emitting unit 20 by executing the calculation described below for each combination of α and β. It is. That is, the combination of α and β representing the optical axis direction of the camera 1 and the setting table have a one-to-one relationship.

Hereinafter, with reference to FIG. 10 and FIG. 11, the calculation executed to determine the emission color of each light emitting unit 20 will be described.
In FIG. 10, the illumination light from one point P in the illuminating device 2 is irradiated to the inclined line FL along one gradient direction in the predetermined fillet 100 on the substrate S, and regular reflection from the inclined line FL to this illumination light is performed. Assuming that light is incident on the camera 1, the relationship between the direction of illumination light from the point P and the regular reflection direction with respect to the inclined line FL is shown. Specifically, FIG. 10A shows the relationship in each direction when the substrate S is viewed from above. Further, (B) is a projection of each vector indicating the direction of illumination light and the regular reflection direction on a virtual vertical plane along the direction of the inclined line FL.

  In the above description, since the specularly reflected light from the inclined line FL is incident on the camera 1, it is considered that the direction of the specularly reflected light is obtained by inverting the imaging direction. Therefore, the regular reflection direction can be expressed by the elevation angle α and the azimuth angle β in the imaging direction. In the figure, the coordinates of the point P are (X, Y, Z), the azimuth angle of the tilt line FL is δ, and the tilt angle is θ.

  First, the relationship represented by the following equations (1) and (2) is established between the elevation angle A and azimuth angle B indicating the direction of illumination light from the point P and the coordinates X, Y, and Z.

Next, as shown in FIG. 10 (A), the direction of the inclined line FL bisects the angle formed by the direction of the illumination light from the point P and the regular reflection direction, and therefore, between the azimuth angles B, β, and δ. The relationship can be expressed as follows.
B−β = (δ−β) × 2
Therefore, δ = (B + β) / 2 (3)

Next, in FIG. 10B, the elevation angle of the vector generated by projecting the direction of the illumination light onto the virtual vertical plane along the inclined line FL is A ′, and the regular reflection direction is projected onto the vertical plane. Let the elevation angle of the resulting vector be α ′. Since the relationship of these projection vectors with respect to the inclination line FL reflects the relationship between the illumination light and the regular reflection light, the relationship between the elevation angles A ′ and α ′ and the inclination angle θ can be expressed as follows. it can.
(Α′−A ′) / 2 = 90 ° − (A ′ + θ)
Therefore, A ′ = 180 ° −α′−2 · θ (4)

  Next, assuming that the projection point of the point P onto the vertical plane is P ′, the relationship between the straight line passing through the points O and P and the straight line passing through the points O and P ′ is seen from directly above, as shown in FIG. Become. Therefore, the line segment OP ′ is expressed as in equation (5).

  Therefore, according to the above expressions (5) and (1), the following relational expression (6) is established between the elevation angle A ′ in FIG. 10B and the elevation angle A indicating the direction of the illumination light. .

Therefore, from equation (6)
A ′ = atan [tan A · cos (B−δ)] (7)
It becomes.

Further, since it is considered that the same relationship as in FIG. 11 and the equation (5) is established between the regular reflection direction and the projection vector, the same relationship as that in the equation (6) is established between the angles α ′ and α. Is established,
α ′ = atan [tan α · cos (β−δ)] (8)
It becomes.

  Therefore, when A ′ and α ′ in the expression (4) are replaced by the right side of the above expressions (7) and (8), the angle θ of the inclined line can be expressed by the following expression (9). .

  Δ in the above equation (9) is obtained from B and β as shown in equation (3). Further, as shown in the equations (1) and (2), the angles A and B can be calculated using the coordinates (X, Y, Z) of the point P, and the angles α and β are the optical axis direction of the camera 1. An angle indicating can be applied. Therefore, the inclination angle θ of the inclination line FL can be obtained by executing the equation (9) using the angles A, B, α, and β.

  The inclination angle θ corresponds to the inclination angle of the inclined surface that receives illumination light from the point P and can be regularly reflected in the directions indicated by α and β, that is, the direction incident on the camera 1. Therefore, if the value of θ can be calculated by the equation (9), it is specified in which angle range the calculated value is included in FIG. 5, and the light of the color corresponding to the specified angle range is represented by the point P. As a result, it is possible to generate an image in which the inclined surface with the angle θ is expressed in a color corresponding to the value of θ.

  Based on the above principle, in this embodiment, one representative point is determined for each light emitting unit 20 of the illumination device 2, and the elevation angle representing the direction of the illumination light with the coordinates of each representative point being (X, Y, Z). The inclination angle θ is calculated by calculating A and the azimuth angle B, and executing the equations (3) and (9) using these angles, the elevation angle α and the azimuth angle β representing the imaging direction. Then, based on the relationship shown in FIG. 5, for each light emitting unit 20, the color corresponding to the calculated value of the inclination angle θ is determined as the light emission color of the light emitting unit 20, and the determined light emission color is identified by the light emitting unit 20. Create a setting table associated with the information.

As described above, in order to create a setting table for illumination control, the illumination direction of each light emitting unit 20 and the imaging direction of the camera are required. As described above, since a plurality of imaging directions are set in the perspective imaging mode, a setting table is created and registered for each imaging direction.
Also for the direct-view imaging mode, it is necessary to create one setting table and register it in the memory. In this case, the setting table defines the light emission colors of the light emitting units 20 so that each of the red, green, and blue colors represents an inclined surface having the angle range shown in FIG.

FIG. 12 shows the flow of processing executed by the above-described inspection apparatus for one inspection target substrate, focusing on control related to imaging.
The process will be described with reference to the reference numerals of the respective steps in the figure. First, in ST1, a substrate to be inspected is carried onto a substrate support table.

  The mirror unit 3 at this time is set to a position (see FIG. 2A) where the direct-view imaging mode is executed. Accordingly, in ST2, the illumination color of each light emitting unit 20 is controlled using a setting table for direct-view imaging.

  Under illumination by this control, the optical system (including the camera 1, the illumination device 2, and the mirror unit 3) is aligned with a predetermined imaging target area registered in the memory, and imaging is executed (ST3). Furthermore, image processing and determination for fillet inspection are executed based on the registered inspection data for the inspection target component included in the image generated by the imaging (ST4).

  Hereinafter, until the inspection of the parts to which the direct-view imaging mode is applied is completed, imaging is sequentially performed while changing the imaging target region, and image processing and determination processing for inspection are executed.

  When the inspection in the direct-view imaging mode ends, ST5 and 6 become “YES” and the process proceeds to ST7. In this step, focusing on one component to which the perspective imaging mode is applied, the imaging direction registered for the focused component (usually including a plurality of directions) is read.

Then, paying attention to the read imaging direction in order, each step of ST8 to ST11 is executed.
In ST8, by adjusting the height and direction of the mirror unit 3 and the inclination of the reflection mirrors 31 and 32 based on the control data corresponding to the imaging direction of interest, adjustment is made so that the imaging direction of the camera 1 becomes the direction of interest. To do. In ST9, the emission color of each light emitting unit 20 of the illumination device 2 is controlled based on the setting table corresponding to the imaging direction of interest. In ST10, the optical system is aligned with the component to be inspected under illumination by the above-described control, and imaging is performed. In ST11, image processing and determination processing for inspection are executed using the generated image. To do.

  When the processes of ST8 to 11 are executed for all the imaging directions read in ST7, ST12 becomes “YES”. In the following, the process according to the same procedure is repeatedly executed while paying attention to the parts to which the perspective imaging mode is applied in order. When the processing for all the target components is completed, ST6 becomes “NO”, so the board is unloaded (ST13), and then the processing is terminated.

  In the above embodiment, a plurality of imaging directions for the perspective imaging mode are determined in advance, and control data related to the setting of these imaging directions and a setting table for illumination control corresponding to each imaging direction are registered in the memory. However, the imaging direction can be changed or added as appropriate in accordance with the user's designation operation. Specifically, the control unit 60 updates or newly creates control data and a setting table in accordance with a change in imaging direction or an additional designation.

On the other hand, instead of registering the setting table for lighting control, the relationship table representing the relationship between the inclination angle and the color shown in FIG. 5 is registered in the memory, and in teaching, for each component to which the perspective imaging mode is applied, After arbitrarily determining the imaging direction suitable for the component, the emission color of each light emitting unit may be determined based on the imaging direction and the relation table.
Specifically, for each light emitting unit, the calculation based on the above equations (3) and (9) is performed based on the illumination direction of the light emitting unit and the determined imaging direction, and illumination from the light emitting unit is performed. After obtaining the inclination angle θ of the inclined surface on which the regular reflection light with respect to the light can be incident on the camera 1, the relation table shown in FIG. 5 is collated with this angle θ to correspond to the angle range including the angle θ. A color is specified, and this color is determined as the emission color of the light emitting unit. Furthermore, by registering each luminescent color determined by each light emitting unit in the memory in association with the imaging direction, for inspection, for each component corresponding to the perspective imaging mode, illumination based on the registered information and the imaging direction, respectively. Can be set and imaging can be performed.

  In the above embodiment, only purple is assigned to the angle range in which the illumination color cannot be reflected in the image in the direct-view imaging mode. However, the present invention is not limited to this, and the angle range is further divided into a plurality of parts. The inclined surface corresponding to each range may be represented by different colors.

  In the above embodiment, the azimuth angle β in the imaging direction is changed by rotating the reflecting mirror while maintaining the facing relationship, but instead, the substrate is rotated by rotating the substrate support table. You may make it change the relative direction of the imaging direction on the basis of.

It is a block diagram of a board | substrate external appearance inspection apparatus. It is explanatory drawing which shows the direct view imaging mode and perspective imaging mode which are performed with said test | inspection apparatus. It is a circuit diagram which shows the electric constitution of a light emission part. It is explanatory drawing which shows the example of a setting of the light emission area | region of the illuminating device at the time of a perspective imaging mode. It is a table which shows the relationship between the inclination angle of a fillet, and the color which appears in an image. It is explanatory drawing which shows the specific example of the imaging in a perspective imaging mode. It is explanatory drawing which shows the parameter showing an illumination direction and an imaging direction. It is explanatory drawing which shows the parameter showing an illumination direction and an imaging direction. It is explanatory drawing which shows the specific example of the method of changing an imaging direction. It is explanatory drawing which shows the principle of the calculation for determining the luminescent color of each light emission part in a perspective imaging mode. It is explanatory drawing which shows the principle of the calculation for determining the luminescent color of each light emission part in a perspective imaging mode. It is a flowchart of the process performed at the time of a test | inspection. It is explanatory drawing which shows the optical system of the conventional board | substrate external appearance inspection apparatus. It is explanatory drawing which shows the relationship between the inclined surface which has the largest inclination angle recognizable by the optical system of FIG. 13, and illumination light and regular reflection light.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera 2 Illumination device 3 Mirror unit 6 Control processing device 20 Light emission part 21 LED chip 31, 32 Reflection mirror 60 Control part 101 Fillet C Center line of illumination apparatus S Substrate F Inclination line

Claims (5)

A board on which multiple types of components are soldered is targeted for inspection.
A lighting device having a configuration in which a plurality of light emitting units capable of switching the emission color are arranged over the entire circumference so that the incident angle increases as the distance from the center increases, the upper side of the substrate being aligned with the center line in the vertical direction And an imaging device for color imaging is arranged so as to image the substrate from obliquely above,
By controlling the emission color of each light emitting unit so that a plurality of groups with different emission colors are generated according to the change in the incident angle in the arrangement of the light emitting unit in each direction of the illumination device, and by imaging under illumination by the control In the method of inspecting the suitability of the surface state of the soldering part included in the field of view of the imaging device using the color pattern in the generated image,
An angle range in which an angle range that is steeper than the above range is continuously divided into a range of inclination angles of an inclined surface capable of specularly reflecting light from the illumination device in a direction along the center line of the illumination device is divided into a plurality of ranges. , And associate different colors with the multiple angle ranges resulting from this division,
With respect to each light emitting unit of the illumination device, it is possible to regularly reflect illumination light from the light emitting unit in a direction incident on the imaging device based on the illumination direction of the light emitting unit with respect to the substrate and the imaging direction of the imaging device. Identify the inclination angle of the inclined surface, determine a color corresponding to the angle range including the specified inclination angle among a plurality of angle ranges generated by the division, as the emission color of the light emitting unit,
Control each light emitting unit to turn on the determined emission color, and drive the imaging device under illumination by this control to generate an image for inspection,
A method for inspecting the appearance of a substrate. A board on which multiple types of components are soldered is targeted for inspection.
A lighting device having a configuration in which a plurality of light emitting units capable of switching the emission color are arranged over the entire circumference so that the incident angle increases as the distance from the center increases, the upper side of the substrate being aligned with the center line in the vertical direction And an imaging device for color imaging above the substrate, a direct-view imaging state in which the substrate is imaged from a direction along the center line of the illumination device, and a perspective imaging state in which the substrate is imaged obliquely from above Switchable and placed,
The imaging device is set to a direct-view imaging state or a perspective imaging state in accordance with a region to be inspected on the substrate, and a plurality of light emission colors differ depending on a change in an incident angle in an array of light emitting units in each direction of the illumination device The surface state of the soldering part included in the field of view of the imaging device is controlled by using the color pattern in the image generated by imaging under illumination by controlling the emission color of each light emitting unit so that a group of In the method of inspecting the suitability of
When the imaging device is set to the direct-viewing imaging state, the emission color of each light-emitting area in the direct-viewing imaging state is determined so that the boundary position between the groups of the light emitting units of the illumination device is uniform over the entire circumference And
The correspondence between the color in the image and the tilt angle is the same as in the direct-view imaging state for the inclined surface represented by the color corresponding to each emission color of the illumination device in the image captured by the direct-view imaging state. In addition, at least one angle range corresponding to a steeper surface corresponds to a color and an inclination angle in an image obtained by imaging under the perspective imaging state so that a color that does not appear in the image under the direct imaging state corresponds to the at least one angle range. A correspondence relationship is determined, and for each light emitting unit, illumination light from the light emitting unit is directed to the imaging device under the perspective imaging state based on the illumination direction with respect to the substrate of the light emitting unit and the imaging direction of the imaging device under the perspective imaging state. By specifying the inclination angle of the inclined surface that can be regularly reflected in the incident direction, and setting the color corresponding to the angle range including the specified inclination angle as the emission color of the light emitting unit. Determines the emission color of the light emitting units under the perspective imaging state,
Each light emitting unit of the illumination device is controlled to turn on the emission color based on the determination according to the imaging state of the imaging device, and the imaging device is driven under illumination by each light emitting unit, thereby inspecting Generate an image for
A method for inspecting the appearance of a substrate. A plurality of light emitting parts capable of switching the emission color are arranged in a range from the peep hole to the lower end edge of the case over the entire circumference of the case having a peep hole in the center, and the center line of the peep hole is vertically A lighting device arranged above the substrate to be inspected in a state matched to the direction;
An imaging device for color imaging, which is disposed above the inspection target substrate in a state where the optical axis is aligned with the center line of the peephole,
A pair of reflecting mirrors arranged so as to face each other in a direction perpendicular to the center line of the peephole in a state in which the height or inclination of each can be changed in the casing of the lighting device;
Control the imaging direction of the imaging device by setting the height or inclination of each reflecting mirror according to the part to be inspected on the substrate while maintaining one position of each reflecting mirror on the center line of the peephole Imaging direction control means for
Illumination control means for controlling the emission color of each light emitting unit so that a plurality of groups having different emission colors are generated in accordance with the change in the incident angle in the array of light emitting units in each direction of the illumination device;
Appropriateness of the surface condition of the soldering part included in the field of view of the imaging device by inputting an image generated by the imaging device under the control of the imaging direction control means and the illumination control means, and using the color pattern in the input image In the substrate appearance inspection apparatus comprising a determination processing means for determining
The illumination control means includes
Targeting an angle range in which a range of inclination angles of an inclined surface capable of regular reflection of light from the lighting device in a direction along the center line of the lighting device is continued with an angle range steeper than the range. A relationship table in which different colors are associated with a plurality of angle ranges set by dividing the angle range;
For each light emitting unit of the illumination device, the illumination light from the light emitting unit can be regularly reflected in the direction of incidence on the imaging device based on the illumination direction of the light emitting unit with respect to the substrate and the imaging direction of the imaging device. A light emission color that executes the process of determining the light emission color of the light emitting unit by specifying the inclination angle of a specific inclined surface and collating the relation table with the specified inclination angle for each imaging direction set by the imaging control means A determination means;
And controlling the emission color of each light emitting unit based on the determination of the emission color determining means for the imaging direction according to the imaging direction of the imaging device.
Board visual inspection equipment. A plurality of light emitting parts capable of switching the emission color are arranged in a range from the peep hole to the lower end edge of the case over the entire circumference of the case having a peep hole in the center, and the center line of the peep hole is vertically A lighting device arranged above the substrate to be inspected in a state matched to the direction;
An imaging device for color imaging, which is disposed above the inspection target substrate in a state where the optical axis is aligned with the center line of the peephole,
A pair of reflecting mirrors, which are opposed to each other along a direction perpendicular to the center line of the peep hole in the casing of the lighting device, and are supported so as to reciprocate along the facing direction,
A first positioning for stopping each reflecting mirror in a state of being opposed to each other across the center line, and a second positioning for stopping each reflecting mirror so that one reflecting mirror is positioned on the center line, Imaging control means for switching the imaging state of the imaging device by switching and executing according to the part to be inspected on the substrate;
Illumination control means for controlling the emission color of each light emitting unit so that a plurality of groups having different emission colors are generated in accordance with the change in the incident angle in the array of light emitting units in each direction of the illumination device;
An image generated by the imaging device is input under the control of the imaging control unit and the illumination control unit, and the suitability of the surface state of the soldering part included in the field of view of the imaging device is determined using the color pattern in the input image. In the substrate visual inspection apparatus comprising the discrimination processing means for discriminating,
The illumination control means is set as a setting table indicating the relationship between each light emitting section and the light emission color in a direct-view imaging state in which the imaging means images the substrate from the direction along the center line of the peephole by the first positioning. And a setting table used when the imaging unit is set in a perspective imaging state in which the imaging unit images the substrate from obliquely above by the second positioning, respectively. Comprising a registration means, referring to a setting table corresponding to the imaging state set in the imaging device, controlling the emission color of each light emitting unit;
In the setting table used when setting the direct-view imaging state, the emission color of each light emitting area is registered so that the boundary position between the groups of the light emitting units of the illumination device is uniform over the entire circumference,
In the setting table used when setting the perspective imaging state,
The correspondence between the color in the image and the inclination angle of the inclined surface represented by the color corresponding to each light emission color of the illumination device in the image captured under the direct-view imaging state is the image under the direct-view imaging state. And the color and inclination in the image obtained by imaging under the perspective imaging state so that the color that did not appear in the image under the direct imaging state corresponds to at least one angle range corresponding to the steeper surface. The correspondence relationship with the angle is determined, and for each light emitting unit, the illumination light from the light emitting unit under the perspective imaging state is based on the illumination direction with respect to the substrate of the light emitting unit and the imaging direction of the imaging device under the perspective imaging state. The inclination angle of the inclined surface that can be regularly reflected in the direction incident on the imaging device is specified, and the color corresponding to the angle range including the specified inclination angle is used as the emission color of the light emitting unit. By constant, the emission color of each light emitting portion defined is registered,
Board visual inspection equipment. Each of the reflection mirrors is supported such that the height or inclination of each of the reflection mirrors can be changed while maintaining a facing relationship along a direction orthogonal to the center line of the lighting device.
The imaging control means changes the imaging direction of the imaging device to any one of a plurality of directions by changing the height or inclination of each reflecting mirror when performing the second positioning with respect to the reflecting mirror. Set,
In the registration unit of the illumination control unit, a setting table is individually registered for each of a plurality of imaging directions under the perspective imaging state,
The illumination control unit changes the emission color of each light emitting unit using a setting table corresponding to the switched imaging direction each time the imaging direction of the imaging device under the perspective imaging state is switched by the imaging control unit.
The board | substrate external appearance inspection apparatus described in Claim 4.

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