JP5930284B2 - Illumination apparatus, imaging apparatus, screen printing apparatus, alignment method, and substrate manufacturing method - Google Patents

Description

  The present technology relates to an illumination device, an imaging device, a screen printing device, an alignment method, and a substrate manufacturing method that can be used, for example, when an electronic component is mounted on a substrate.

  Conventionally, screen printing is known as a technique for printing cream solder on a circuit board. In screen printing, a screen formed by a mesh or metal mask is superimposed on a circuit board. Solder is supplied on the screen, and the squeegee is slid on the screen. Thereby, solder is pushed out from the opening formed in the screen, and a predetermined pattern is printed on the circuit board.

  For example, Patent Literature 1 describes an inspection method for the purpose of making it possible to inspect the print state of a screen printed portion of a circuit board only with a camera. In this inspection method, a camera is disposed between the screen mask and the circuit board. The camera has a structure capable of photographing both the screen mask and the circuit board. That is, the camera is provided with illumination for photographing the screen mask at a position facing the screen mask. Further, illumination for photographing the circuit board is provided at a position facing the circuit board (see FIG. 1 in Patent Document 1). This camera is appropriately used to inspect the printing state of the screen printing portion.

JP 2008-82714 A

  Screen printing as described above requires highly accurate alignment between the screen and the circuit board. For example, the circuit board and the screen are photographed using the camera described in Patent Document 1. Alignment marks provided on the screen and the circuit board are detected from the captured images. Based on the detection result, the screen and the circuit board are aligned. In this case, it is required that the alignment mark is clearly photographed by the camera and the alignment mark is recognized with high accuracy.

  In view of the circumstances as described above, an object of the present technology is to provide, for example, an illumination device, an imaging device, a screen printing device, an alignment method, and a substrate that can clearly photograph an alignment mark or the like provided on a screen or the like. It is in providing the manufacturing method of.

In order to achieve the above object, an illumination device according to an embodiment of the present technology includes an illumination unit and a translucent mirror.
The illumination unit includes one or more light sources that emit illumination light to a first subject, and irradiates illumination light from the light source onto an illumination optical axis to the first subject.
The translucent mirror is disposed on the illumination optical axis, transmits the illumination light irradiated by the illumination unit, and is coaxial with the illumination optical axis from the first subject irradiated by the transmitted illumination light. The first reflected light is reflected on the imaging optical axis of the imaging apparatus that captures the first subject.

  In this illumination apparatus, illumination light is irradiated on the illumination optical axis for the first subject by the illumination unit. A translucent mirror is disposed on the illumination optical axis. The semi-transparent mirror transmits the illumination light irradiated by the illumination unit. Further, the first reflected light that is reflected from the first subject and irradiated with the transmitted illumination light and is coaxial with the illumination optical axis is reflected on the photographing optical axis of the imaging device that photographs the subject. As a result, the first subject is coaxially illuminated. As a result, for example, an alignment mark provided on a screen or the like can be clearly photographed.

The illumination optical axis may be perpendicular to the first subject.
In this illumination device, the illumination unit irradiates the illumination light perpendicularly to the first subject. The regularly reflected light of the illumination light irradiated vertically becomes the first reflected light. The first reflected light is reflected on the photographing optical axis, so that the first subject is clearly photographed.

  The illumination unit includes a support unit disposed at a position facing the first subject, an opening formed in the support unit through which the illumination optical axis passes, and a side of the support unit opposite to the first subject. And it may have a plurality of light sources provided around the opening, and a first shutter having a reflection surface that reflects the illumination light from the plurality of light sources to the opening.

  In this illuminating device, a plurality of light sources are provided on a side opposite to the first subject of the support portion disposed at a position facing the first subject. Illumination light emitted from the plurality of light sources is reflected by the reflection surface of the first shutter. The reflected illumination light is irradiated on the illumination optical axis through an opening formed in the support portion. Thereby, unnecessary light such as external light can be prevented, and illumination light from a plurality of light sources can be accurately irradiated onto the illumination optical axis.

The illumination device may further include a connection unit that connects the illumination device to the imaging device such that a photographing optical axis of the imaging device is orthogonal to the illumination optical axis. In this case, the translucent mirror may reflect the first reflected light on the photographing optical axis by reflecting the first reflected light from the first subject at a right angle.
Accordingly, for example, the first subject can be photographed by appropriately moving the imaging device to which the present illumination device is connected in a state where the photographing optical axis is parallel to the first subject.

The first shutter may be movable so that illumination light from the light source is irradiated to a second subject facing the first subject in the direction of the illumination optical axis.
In this case, the translucent mirror reflects the second reflected light from the second subject irradiated with the illumination light in a direction opposite to the first reflected light in the direction of the photographing optical axis. May be.
The illuminating device may further include a reflecting unit that reflects the second reflected light reflected by the semi-transparent mirror onto the photographing optical axis.

  In this lighting device, the first shutter is provided so as to be movable. As the first shutter moves, the illumination light from the light source is irradiated to the second subject that faces the first subject in the direction of the illumination optical axis. The second reflected light from the second subject is irradiated onto the photographing optical axis via the semitransparent mirror and the reflecting part. Therefore, by using this illumination device, the first and second subjects can be appropriately photographed with illumination light from the light source.

The illumination device is disposed on the photographing optical axis between the translucent mirror and the first subject, and absorbs the second reflected light from the second subject that passes through the translucent mirror. A second shutter may be further included.
Thereby, when the second subject is photographed, for example, external light, reflected light from the first subject, or the like can be prevented. As a result, the second subject can be clearly photographed.

The illumination device may further include an auxiliary illumination unit.
The auxiliary illumination unit includes an auxiliary support unit, an auxiliary opening, and one or more auxiliary light sources.
The auxiliary illumination unit is disposed between the translucent mirror and the first subject.
The auxiliary opening is an opening through which the illumination optical axis formed in the auxiliary support portion passes.
The one or more auxiliary light sources are provided around the auxiliary opening and irradiate the first subject with auxiliary illumination light.
In this illumination device, an auxiliary illumination unit having an auxiliary light source or the like is provided between the translucent mirror and the first subject. Thereby, for example, the first subject illuminated coaxially can be clearly photographed.

The regular reflectance of the first subject may be larger than the regular reflectance of the second subject.
In this illuminating device, the first subject having a large regular reflectance is coaxially illuminated by the illumination unit. Then, illumination light is emitted from the light source toward the second subject having a small regular reflectance. As a result, the first and second subjects are clearly photographed.

The first subject may be a screen for printing a paste material. In this case, the second subject may be a print target on which the paste material is printed using the screen.
As described above, the present illumination device may be used for photographing the screen and the printing object facing in the direction of the illumination optical axis. Thereby, for example, the alignment marks provided on the screen and the printing object can be clearly photographed.

An imaging device according to an embodiment of the present technology includes an imaging unit, an illumination unit, and a translucent mirror.
The imaging unit photographs a subject.
The illumination unit includes one or more light sources that emit illumination light to the subject, and irradiates illumination light from the light source onto an illumination optical axis for the subject.
The translucent mirror is disposed on the illumination optical axis, transmits the illumination light irradiated by the illumination unit, and is coaxial with the illumination optical axis from the subject irradiated by the transmitted illumination light. The reflected light is reflected on the photographing optical axis of the imaging unit.

A screen printing apparatus according to an embodiment of the present technology includes an imaging unit, an illumination unit, an optical system, and a screen printing unit.
The imaging unit can capture an image of the screen and a print object that faces the screen.
The illumination unit includes a support unit, an opening, a plurality of light sources, and a shutter.
The support portion is disposed between the screen and the print object.
The opening is formed in the support portion through which an illumination optical axis to the screen parallel to the direction in which the screen and the printing object face each other.
The plurality of light sources are provided on the printing object side of the support portion and around the opening.
The shutter has a reflection surface that reflects the illumination light from the plurality of light sources to the opening, and is movable when the print object is irradiated with illumination light from the plurality of light sources.
The optical system includes a translucent mirror and a reflecting portion.
The translucent mirror is disposed on the illumination optical axis between the illumination unit and the screen, transmits the illumination light irradiated by the illumination unit, and passes from the screen irradiated by the transmitted illumination light. The first reflected light that is coaxial with the illumination optical axis is reflected on the photographing optical axis of the imaging unit, and the second object from the print object irradiated with the illumination light by the movement of the shutter. The reflected light is reflected in the direction opposite to the first reflected light in the direction of the photographing optical axis.
The reflection part reflects the second reflected light reflected by the translucent mirror on the photographing optical axis.
The screen printing unit adjusts the relative position of the screen and the print object based on the images of the screen and the print object captured by the imaging unit, and the adjusted position The paste material is supplied onto the screen placed on the print object, and the supplied paste material is printed on the print object.

The alignment method according to an aspect of the present technology includes the following steps.
Illumination light emitted from one or more light sources toward the second subject between the first subject and the second subject facing the first subject is used as the one or more light sources and the first subject. The reflection light of the shutter arranged between the two subjects is reflected to the first subject, and the illumination light is irradiated onto the illumination optical axis for the first subject.
The translucent mirror disposed on the illumination optical axis transmits the illumination light irradiated on the illumination optical axis and is coaxial with the illumination optical axis from the first subject irradiated by the transmitted illumination light. The first reflected light is reflected on the photographing optical axis of the imaging device that photographs the first subject, and the first subject is photographed.
The second subject is irradiated with illumination light from the one or more light sources by moving the shutter.
The semi-transparent mirror reflects the second reflected light from the second subject irradiated with the illumination light in a direction opposite to the first reflected light in the direction of the photographing optical axis.
The second reflected light reflected by the semi-transparent mirror is reflected on the photographing optical axis by a reflecting unit to photograph the second subject.
The relative positions of the first and second subjects are adjusted based on the images of the first and second subjects taken by the imaging device.

The manufacturing method of the board | substrate which concerns on one form of this technique includes the following processes.
Illumination light emitted from one or more light sources toward the substrate between the screen and the substrate facing the screen is reflected on a reflection surface of a shutter disposed between the one or more light sources and the substrate. The illumination light is reflected on the screen, and the illumination light is irradiated on the illumination optical axis to the screen.
A translucent mirror disposed on the illumination optical axis transmits the illumination light irradiated on the illumination optical axis, and is coaxial with the illumination optical axis from the screen irradiated by the transmitted illumination light. The reflected light of 1 is reflected on the photographing optical axis of the imaging device that photographs the screen, and the screen is photographed.
The shutter is moved to irradiate the substrate with illumination light from the one or more light sources.
The semi-transparent mirror reflects the second reflected light from the substrate irradiated with the illumination light in a direction opposite to the first reflected light in the direction of the photographing optical axis.
The reflection part reflects the second reflected light reflected by the translucent mirror onto the photographing optical axis to photograph the substrate.
The relative positions of the screen and the substrate are adjusted based on the images of the screen and the substrate taken by the imaging device, and the screen is placed on the substrate at the adjusted position. Then, the paste material is printed on the substrate by screen printing, and the component is mounted on the substrate on which the paste material is printed.

  As described above, according to the present technology, for example, an alignment mark provided on a screen or the like can be clearly photographed.

It is a typical side view showing a solder printer, for example, as a screen printer concerning one embodiment of this art. FIG. 2 is a schematic plan view of the solder printing apparatus illustrated in FIG. 1, including a block diagram illustrating a configuration of a control system of the solder printing apparatus. It is typical sectional drawing which shows the structural example of the camera unit which concerns on this embodiment. FIG. 4 is a schematic diagram illustrating a configuration example of an illumination unit illustrated in FIG. 3 (illustration of a shutter is omitted). It is a schematic diagram which shows the other structural example of the illumination part shown in FIG. It is a flowchart which shows an example of the solder printing process by the solder printer which concerns on this embodiment. It is a flowchart which shows an example of the solder printing process by the solder printer which concerns on this embodiment. It is a schematic diagram for demonstrating the imaging | photography process by the camera unit shown in FIG. It is a schematic diagram for demonstrating the imaging | photography process by the camera unit shown in FIG. It is a flowchart which shows an example of the board | substrate mounting process in which an electronic component is mounted in the circuit board which concerns on this embodiment. It is the typical figure and photograph for demonstrating specifically the problem at the time of imaging | photography the screen where the surface is close to a mirror surface. It is a schematic diagram for demonstrating that coaxial epi-illumination is used paying attention to the regular reflectance and diffuse reflectance of a to-be-photographed object. It is a schematic diagram for demonstrating that coaxial epi-illumination is used paying attention to the regular reflectance and diffuse reflectance of a to-be-photographed object. It is a schematic diagram which shows the structure of the general illumination unit for implement | achieving coaxial epi-illumination. It is a schematic diagram which shows the structural example for implement | achieving pseudo coaxial epi-illumination. It is a schematic diagram which shows the modification of the illuminating device shown in FIG.

  Hereinafter, embodiments according to the present technology will be described with reference to the drawings.

[Configuration of solder printing equipment]
FIG. 1 is a schematic side view showing, for example, a solder printing apparatus as a screen printing apparatus according to an embodiment of the present technology. FIG. 2 is a schematic plan view of the solder printing apparatus 100 shown in FIG. 1, and includes a block diagram showing a configuration of a control system of the solder printing apparatus 100.

  The solder printing apparatus 100 is an apparatus that prints paste-like solder, that is, cream solder, on a circuit board W as an object to be printed. In the following description, for the sake of simplicity, the right side in FIGS. 1 and 2 is the front part of the solder printing apparatus 100 and the left side is the rear part of the solder printing apparatus 100 for convenience.

  The solder printing apparatus 100 includes a stage mechanism 30 as a support mechanism that supports the circuit board W and a screen 5 that is disposed so as to face the circuit board W supported by the stage mechanism 30. Prepare.

  The solder printing apparatus 100 includes a squeegee unit 20 disposed on the screen 5 on the front side of the solder printing apparatus 100, a squeegee moving mechanism 19 that moves the squeegee unit 20 along the Y-axis direction, and a solder printing apparatus. A supply unit 10 for supplying cream solder onto the screen 5 on the rear side of 100 and a supply unit moving mechanism 18 for moving the supply unit 10 along the X and Y axes are provided.

  The screen 5 includes, for example, a frame 5a and a mask portion 5b in the frame 5a. A screen support mechanism 6 that fixes and supports the frame 5 a of the screen 5 is provided on the upper portion of the stage mechanism 30. In FIG. 2, the screen 5 and the screen support mechanism 6 are not shown.

  The circuit board W has lands which are a plurality of conductive pads, and cream solder is applied on the lands via a mask portion 5b. That is, the mask portion 5b is provided with a number of holes corresponding to the land pattern of the circuit board W, and the cream solder is supplied onto the lands from the mask portion 5b through the holes.

  The stage mechanism 30 includes a mounting table 32 on which the circuit board W is mounted, a clamp mechanism 31 that clamps both sides of the circuit board W mounted on the mounting table 32, and the mounting table 32 on the X, Y, and Z axes. The drive unit 33 is moved. The clamp mechanism 31 is operated by, for example, an actuator having a spring (not shown). The mounting table 32 may have a device for holding the circuit board W by a vacuum chuck.

  The drive unit 33 aligns the circuit board W in the XY plane with respect to the screen 5 supported by the screen support mechanism 6 by moving the mounting table 32 along the X and Y axes. The drive unit 33 moves the mounting table 32 up and down in the Z-axis direction to bring the circuit board W mounted on the mounting table 32 into contact with the screen 5.

  As shown in FIGS. 1 and 2, the supply unit moving mechanism 18 is disposed on the upper portion of the screen 5. The supply unit moving mechanism 18 extends along the X axis moving mechanism 16 that moves the supply unit 10 along the X axis direction, and moves along the X axis direction of the supply unit 10. And a guide rail 16a for guiding.

  The supply unit moving mechanism 18 extends along the Y-axis moving mechanism 17 and the Y-axis moving mechanism 17 that moves the supply unit 10 along the Y-axis direction, and extends along the Y-axis direction of the supply unit 10. And a guide rail 17a for guiding the movement. In the Y-axis moving mechanism 17, two guide rails 17a are provided. The X-axis moving mechanism 16 is connected to these guide rails 17a.

  As the X-axis moving mechanism 16 and the Y-axis moving mechanism 17, for example, a motor, an air cylinder, a ball screw, a belt, a rack and pinion, a linear motor, or the like is used.

  As shown in FIG. 2, the squeegee unit 20 is driven by a squeegee moving mechanism 19, and the squeegee moving mechanism 19 shares the guide rail 17 a of the Y-axis moving mechanism 17. The squeegee moving mechanism 19 has a frame member 9 that moves along the guide rail 17 a and supports the squeegee unit 20.

  The motor that is the drive source of the squeegee moving mechanism 19 and the motor that is the drive source of the Y-axis moving mechanism 17 of the supply unit 10 are different, and the supply unit 10 and the squeegee 21 (21a and 21b) are respectively Driven independently.

  As the squeegee moving mechanism 19, a ball screw, a belt, or the like is used as appropriate, similarly to the X-axis moving mechanism X and Y-axis moving mechanism 17 described above. The X-axis moving mechanism X, the Y-axis moving mechanism 17 and the squeegee moving mechanism 19 do not have to be configured using the same members.

  The squeegee unit 20 is configured so that, for example, the squeegee 21 (the front squeegee 21a and the rear squeegee 21b) faces the screen 5, and these squeegees 21a and 21b are along the Y-axis direction that is the moving direction of the squeegee unit 20. It has squeegee holders 22 (22a and 22b) for holding them side by side.

  Further, the squeegee holders 22a and 22b hold the front squeegee 21a and the rear squeegee 21b so that the length directions thereof are along the X-axis direction. The squeegee holder 22 is driven independently in the vertical direction by an air cylinder (not shown).

  By appropriately driving the squeegee 21, the solder supplied on the screen is printed on the circuit board W in a predetermined pattern. When the squeegee 21 is driven, the distance between the distance sensor 57 shown in FIG. 2 and the cream solder rolled on the screen 5 is measured.

  As the distance sensor 57, for example, a reflective optical sensor is used. By measuring the distance by the distance sensor 57, the diameter or amount of the cream solder rolled by the squeegee 21 is estimated. Based on the estimated diameter or amount of cream solder, for example, the supply operation of the cream solder by the supply unit 10 and the operation of the squeegee 21 can be appropriately controlled.

  As shown in FIG. 1, the solder printing apparatus 100 includes a movable camera unit 58 disposed at a height position between the circuit board W placed on and supported by the placing table 32 and the screen 5. ing. The camera unit 58 is used for alignment between the screen 5 and the circuit board W.

  The camera unit 58 is supported by the carriage 13. The carriage 13 is connected to a guide rail 11 that extends in the lateral direction and that is spaced at a predetermined interval in the vertical direction. The guide rail 11 is provided on the other side of the drive unit 33 (the back side in FIG. 1), and the carriage 13 moves on the other side of the drive unit 33 in the Y-axis direction. Thereby, the camera unit 58 can move in the Y-axis direction.

  The camera unit 58 is supported by a support base 29 extending in the X-axis direction so as to be movable in the X-axis direction. The camera unit 58 is supported by the carriage 13 via the support base 29. For example, the carriage 13 moves along the guide rail 11 to a predetermined position in the Y-axis direction. The camera unit 58 moves on the support base 29 to a predetermined position in the X-axis direction. Thus, in this embodiment, the camera unit 58 is movable in the X and Y axis directions. In addition, the structure for moving the camera unit 58, a moving method, etc. are not limited.

  The camera unit 58 can move in two dimensions in the X and Y axis directions and can photograph both the screen 5 and the circuit board W. By this photographing, for example, images of alignment marks respectively provided on the screen 5 and the circuit board W are acquired. The screen 5 and the circuit board W are aligned based on the image. The camera unit 58 will be described in detail later.

  Further, another carriage 14 is movably connected to the guide rail 11. A cleaning unit 25 is supported on the carriage 14. The cleaning unit 25 is for cleaning the lower surface of the screen 5 with the cleaning tape 26 shown in FIG. The cleaning tape 26 is fed from the feeding roller 27 of the cleaning unit 25, and the cleaning tape 26 that has finished cleaning is taken up by the take-up roller 28.

  The solder printing apparatus 100 is connected to a conveyor (not shown) for carrying the circuit board W into the solder printing apparatus 100 and carrying out the circuit board W after printing of the circuit board W is completed. For example, a belt or roller type conveyor is used, and the circuit board W is conveyed in the X-axis direction shown in FIGS.

  As shown in FIG. 2, the control system of the solder printing apparatus 100 includes a host computer 50, an X-axis movement mechanism controller 51, a Y-axis movement mechanism controller 52, a supply unit controller 53, a stage mechanism controller 54, a squeegee movement mechanism controller 55, A squeegee unit controller 56 is provided.

  The X-axis movement mechanism controller 51 controls driving of the X-axis movement mechanism 16 of the supply unit 10. The Y-axis moving mechanism controller 52 controls driving of the Y-axis moving mechanism 17 of the supply unit 10. The supply unit controller 53 controls driving of an elevator motor and an opening / closing member (not shown) included in the supply unit 10. The stage mechanism controller 54 controls driving in the horizontal plane of the mounting table 32 and raising / lowering driving by the stage mechanism 30. The squeegee moving mechanism controller 55 controls the movement of the squeegee unit 20 along the Y-axis direction. The squeegee unit controller 56 controls the vertical movement of the front squeegee 21a and the rear squeegee 21b.

  The host computer 50 controls the above controllers in an integrated manner. The host computer 50 is also connected to a distance sensor 57 and a camera unit 58. The host computer 50 receives information acquired from the distance sensor 57 and the camera unit 58, and executes a predetermined process based on the information.

  The host computer 50 controls the operation of the camera unit 58 and acquires images of the screen 5 and the circuit board W. Then, based on the images of the screen 5 and the circuit board W, the relative positions of the screen 5 and the circuit board W are adjusted. Thereby, the alignment between the screen 5 and the circuit board W is executed.

  Under the control of the host computer 50, solder is supplied onto the screen 5 placed on the circuit board W at the adjusted position. The squeegee 21 is driven, and the supplied solder is printed on the circuit board W. Thus, the host computer 50 also functions as a screen printing unit according to the present embodiment.

  Each of the above controllers may be realized by hardware, or may be realized by both software and hardware. When implemented in both software and hardware, the hardware includes at least a storage device that stores software programs. The same applies to the host computer 50.

  The hardware typically includes a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate). Array), ASIC (Application Specific Integrated Circuit), network interface, and the like. The same applies to the host computer 50.

[Configuration of camera unit]
FIG. 3 is a schematic cross-sectional view illustrating a configuration example of the camera unit 58 according to the present embodiment.

  The camera unit 58 includes an imaging device 60, a lens barrel 65, and a lighting device 70 according to the present embodiment. The imaging device 60 is shown in a side view, not a sectional view.

  The imaging device 60 includes an imaging control unit, an imaging element, and an imaging optical system (not shown). As the image sensor, for example, a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD) sensor is used. The imaging optical system forms a subject image on the imaging surface of the imaging element. For example, the imaging control unit drives the imaging device based on an instruction from a CPU or the like, and performs signal processing on an image signal output from the imaging device. The imaging control unit sets the zoom magnification of the image to be captured by controlling the imaging optical system.

  In the present embodiment, the alternate long and short dash line shown in FIG. 3 is the imaging optical axis P of the imaging device 60. Therefore, an image of the subject is generated based on the light incident on the image sensor along the photographing optical axis P. As shown in FIG. 3, the direction of the photographing optical axis P is perpendicular to the Z-axis direction in which the screen 5 and the circuit board W face each other (that is, parallel to the Y-axis direction).

  A lens barrel 65 is connected to the mount portion 61 of the imaging device 60. The lens barrel 65 has a lens system 66. The light traveling on the photographing optical axis P enters the imaging device 60 via the lens system 66. The configuration of the lens system 66 and the type and number of lenses included in the lens system 66 are not limited.

  The illumination device 70 according to this embodiment is connected to the tip of the lens barrel 65. Therefore, in this embodiment, the illumination device 70 is connected to the imaging device 60 via the lens barrel 65. The illuminating device 70 is connected to the lens barrel 65 by a connection portion (not shown). For example, a configuration using a member such as a screw may be employed as the connecting portion. Or the structure which has a shape which mutually engages with the lens-barrel 65 may be employ | adopted. The configuration of the connection unit and the connection method are not limited.

  In the present embodiment, the screen 5 disposed above the camera unit 58 is the first subject. Then, the circuit board W disposed below the camera unit 58 becomes the second subject. The screen 5 and the circuit board W are opposed to each other in the Z-axis direction.

  As shown in FIG. 3, the illumination device 70 includes a main body 71, an illumination unit 72 provided at the lower part of the main body 71, and a shutter 73 provided at the upper part of the main body 71. The lower part of the main body 71 is the circuit board W side of the main body 71. Therefore, the illumination unit 72 is disposed between the main body 71 and the circuit board W. The upper part of the main body 71 is the screen 5 side of the main body 71. Therefore, the shutter 73 is disposed between the main body 71 and the screen 5.

  An illumination optical system 74 is provided inside the main body 71. Accordingly, the illumination unit 72, the illumination optical system 74, and the shutter 73 are arranged in this order from the circuit board W side in the Z-axis direction where the screen 5 and the circuit board W face each other.

  The illumination unit 72 includes a plurality of light sources 75 that emit illumination light to the screen 5. The number of the light sources 75 is not limited to a plurality, and one or more light sources 75 may be provided. The illumination part 72 irradiates the illumination light from the light source 75 on the illumination optical axis L to the screen 5 shown with the dashed-two dotted line of FIG.

  In the present embodiment, the illumination optical axis L is set in the same direction as the Z-axis direction. Accordingly, the illumination optical axis L is perpendicular to the screen 5. In addition, the illumination device 70 is connected to the imaging device 60 by the connection unit described above so that the imaging optical axis P of the imaging device 60 is orthogonal to the illumination optical axis L.

  The illumination unit 72 has a support unit 76 disposed at a position facing the screen 5 and an opening 77 through which the illumination optical axis L formed in the support unit 76 passes. The illumination unit 72 includes a plurality of light sources 75 provided on the side opposite to the screen 5 of the support unit 76 and around the opening 77, and a reflection surface 78 that reflects illumination light from the plurality of light sources 75 to the opening 77. And a shutter 79 having.

  FIG. 4 is a schematic diagram illustrating a configuration example of the illumination unit illustrated in FIG. 3. FIG. 4 is a view of a plurality of light sources 75 and the like viewed from the circuit board W in the Z-axis direction. The illustration of the shutter 79 is omitted.

  The support portion 76 is a plate-like member and has a circular shape when viewed in the Z-axis direction. As the support portion 76, a substrate on which the wiring portion 80 is formed is used, and the material, type, and the like are not limited. The shape of the support portion 76 is not limited to a circular shape, and may be arbitrarily designed.

  An opening 77 having a circular shape is formed in the center of the support portion 76. The shape and size of the opening 77 are also arbitrary.

  A plurality of light sources 75 are provided around the opening 77. In the present embodiment, an LED (Light Emitting Diode) is used as the light source 75. Illumination light is emitted from the plurality of light sources 75 by power supplied via the wiring portion 80 of the support portion 76. In FIG. 4, the illustration of the wiring unit 80 is simplified. Further, the wavelength (color) of the emitted illumination light is not limited.

  As shown in FIGS. 3 and 4, the plurality of light sources 75 are provided to be inclined at a predetermined angle toward the center of the support portion 76. For example, it is assumed that an illumination object is arranged in front of the plurality of light sources 75. A plurality of light sources 75 are provided so that the illumination light is emitted toward a position where the illumination object intersects with a line passing through the center of the opening 77 (corresponding to the photographing optical axis L in this embodiment). . Accordingly, the plurality of light sources 75 realize oblique illumination with respect to the illumination object arranged in front of the support portion 76.

  The angle at which the plurality of light sources 75 are arranged, that is, the angle of the illumination light emitted to the illumination object is not limited. For example, as shown in FIG. 5, an attachment portion 81 bent at a predetermined angle may be provided on the peripheral side of the support portion 76, and the light source 75 may be provided on the attachment portion 81. For example, with this configuration, the plurality of light sources 75 can be sufficiently tilted.

  The illumination light from the plurality of light sources 75 is not limited to a configuration in which the illumination light is collected on a line passing through the center of the opening 77. Any configuration may be adopted as long as oblique illumination is realized. Other than the LED may be used as the light source 75, and the number of the light sources 75 is arbitrary.

  The shutter 79 included in the illumination unit 72 is disposed between the support unit 76 and the circuit board W. The shutter 79 is disposed at a position facing the support portion 76 and the circuit board W. A surface facing the support portion 76 of the shutter 79 is a reflection surface 78. The reflecting surface 78 reflects illumination light from the plurality of light sources 75 to the opening 77.

  The reflecting surface 78 is realized by forming the shutter 79 with a material having high reflectivity such as stainless steel, aluminum, gold, silver or the like. Alternatively, it may be realized by providing a highly reflective material such as a metal film or a dielectric film on the upper surface of the shutter 79 by vapor deposition or the like. In addition, any method for forming the reflecting surface 78 may be appropriately employed.

  A mirror surface may be formed as the reflecting surface 78. Further, as long as the illumination light from the plurality of light sources 75 can be reflected to the opening 77, a reflection surface 78 that diffusely reflects the illumination light may be formed.

  Hereinafter, the shutter 79 disposed on the circuit board W side is referred to as a first shutter 79, and the shutter 73 disposed on the screen 5 side is referred to as a second shutter 73. The first and second shutters 79 and 73 can be moved in the Y-axis direction by a shutter opening / closing mechanism (not shown) (see arrow A). The configuration of the shutter opening / closing mechanism is arbitrary. The shutter opening / closing mechanism is controlled by a control signal from the host computer 50. As a result, the opening / closing operation (movement operation in the Y-axis direction) of the first and second shutters 79 and 73 is controlled.

  The second shutter 73 disposed on the screen 5 side is used for absorbing light incident from the illumination unit 72 via the illumination optical system 74. Therefore, a light absorption surface 82 is formed on the lower surface of the second shutter 73. The light absorbing surface 82 is formed by performing, for example, black matte coating. Alternatively, the light absorption surface 82 may be formed of a light absorption film such as a black paint film. In addition, a surface treatment or a method for forming the light absorption surface 82 may be used as appropriate.

  The illumination optical system 74 shown in FIG. 3 includes a half mirror 83 as a semitransparent mirror disposed on the illumination optical axis L, and a reflection as a reflection unit disposed perpendicular to the photographing optical axis P of the imaging device 60. Plate 84.

  The half mirror 83 is an optical element that reflects part of the light incident on the half mirror 83 and transmits the other part. Typically, the incident light is branched such that the amount of transmitted light and the amount of reflected light are 1: 1. However, the branching ratio may be set as appropriate.

  As shown in FIG. 3, the half mirror 83 is disposed at an angle of about 45 degrees with respect to the illumination optical axis L. Therefore, the half mirror 83 transmits about 50% of the illumination light irradiated on the illumination optical axis L by the illumination unit 72 as it is onto the illumination optical axis L. Further, the half mirror 83 reflects about 50% of the illumination light irradiated on the illumination optical axis L to the side opposite to the side where the imaging device 60 is disposed when viewed from the half mirror 83 in the direction of the photographing optical axis P. .

  The half mirror 83 transmits about 50% of the light incident from the screen 5 side along the illumination optical axis L as it is to the opening 77 of the illumination unit 72. Further, the half mirror 83 reflects about 50% of the light from the screen 5 side toward the imaging device 60 on the photographing optical axis P.

  The reflection plate 84 is disposed on the opposite side of the imaging device 60 with respect to the half mirror 83. That is, the imaging device 60, the half mirror 83, and the reflection plate 84 are arranged on the photographing optical axis P. As the reflection plate 84, for example, the one exemplified for the first shutter 79 may be used. Note that the reflecting portion 84 and the first shutter 79 do not have to have the same configuration.

  The size of the camera unit 58 according to this embodiment will be described. The numerical values described below are merely examples, and are not limited to these numerical values. The overall size of the camera unit 58 shown in FIG. 3 in the X-axis direction is about 30 mm. The sizes of the Y-axis and Z-axis directions of the imaging device 60 are both about 30 mm. The size of the main body 71 of the lighting device 70 in both the Y-axis and Z-axis directions is also about 30 mm. The total size of the lens barrel 65 and the mount portion 61 in the Y-axis direction is about 50 mm. Accordingly, the overall size of the camera unit 58 in the Y-axis direction is about 110 mm. The diameter of the support part 76 of the illumination part 72 shown in FIG. 4 is about 35 mm. The diameter of the opening 77 is about 8 mm. The plurality of light sources 75 are arranged such that their tips are arranged on a substantially circle having a diameter of about 15 mm. The thickness of the support portion 76 in the Z-axis direction is about 1.8 mm, and the distance from the support portion 76 to the tip of the light source 75 is about 5 mm. The size of each member can be set as appropriate.

  In the present embodiment, the distance from the screen 5 to the circuit board W is about 100 mm. The camera unit 58 having the above size is moved in this space. The distance from the screen 5 to the circuit board W is not limited.

[Operation of solder printing equipment]
The operation of the solder printing apparatus 100 according to the present embodiment will be described focusing on the operation of the camera unit 58. 6 and 7 are flowcharts showing an example of a solder printing process by the solder printing apparatus 100. FIG. 8 and 9 are schematic diagrams for explaining a photographing process by the camera unit 58. FIG.

  In the present embodiment, the screen 5 and the circuit board W are photographed by the camera unit 58 as described below. Then, the alignment mark formed on the screen 5 and the alignment mark formed on the circuit board W are detected. Based on the detection result, the relative position between the screen 5 and the circuit board W is adjusted. Thereby, alignment with the screen 5 and the circuit board W is performed.

  In the present embodiment, alignment marks are formed at two locations on the screen 5. Information on the position of the alignment mark is stored in a storage device of the solder printing apparatus. Accordingly, information on the photographing position for photographing the two alignment marks is also stored in advance as coordinate information.

  Two alignment marks respectively corresponding to the two alignment marks formed on the screen 5 are also formed on the circuit board W. Information on the position of the two alignment marks and information on the photographing position for photographing the alignment mark are also stored in advance.

  Such information may be automatically stored as information on the screen 5 and the circuit board W set in the solder printing apparatus 100. Alternatively, it may be manually input by the user.

  In step 101, it is determined whether the image of the alignment mark formed on the screen 5 has already been captured (step 101). If the image of the alignment mark has not yet been captured (No in step 101), the camera unit 58 is at the shooting position for shooting one of the two alignment marks on the screen 5 side (described as alignment mark A). Is moved (step 102). This is executed based on preset coordinate information.

  As shown in FIG. 8A, the first shutter 79 is closed. Accordingly, the first shutter 79 is disposed at a position facing the plurality of light sources 75. The second shutter 73 is opened. Accordingly, the second shutter 73 is moved in the Y-axis direction (along arrow A) to a position off the illumination optical axis L (step 103).

  Illumination light L1 is emitted from a plurality of light sources 75 that realize oblique illumination. As shown in FIG. 8A, the illumination light L1 is emitted toward the first shutter 79. The illumination light L1 is reflected by the reflection surface 78 of the first shutter 79 to the opening 77 of the support portion 76. Thereby, the illumination light L1 is irradiated on the illumination optical axis L. The illumination light L1 irradiated on the illumination optical axis L enters the half mirror 83. A part of the illumination light L1 passes through the half mirror 83, and the illumination light L2 is irradiated onto the screen 5.

  As shown in FIG. 8B, the first reflected light L3 that is coaxial with the illumination optical axis L from the screen 5 irradiated with the illumination light L2 enters the half mirror 83. In the present embodiment, the illumination optical axis L is set perpendicular to the screen 5. That is, the illumination light L2 is irradiated perpendicularly to the screen 5. Accordingly, the regular reflected light with respect to the illumination light L2 becomes the first reflected light L3.

  The first reflected light L3 is reflected on the photographing optical axis P of the imaging device 60 by the half mirror 83. In the present embodiment, the first reflected light L3 from the screen 5 is reflected by the half mirror 83 at a right angle. Then, the first reflected light L3 is irradiated on the photographing optical axis P.

  Thereby, the screen 5 is photographed and an image of the alignment mark A is photographed (step 104). The first reflected light L3 that is coaxial with the illumination optical axis L is reflected on the photographing optical axis P, and the screen 5 is photographed. Therefore, the screen 5 is photographed by the coaxial epi-illumination.

  Image processing is performed on the captured image of the screen 5, and the alignment mark A is detected (step 105). Thereby, for example, position information of the alignment mark A with respect to a predetermined photographing position is calculated. The image processing and the position calculation process are executed by a software block that functions as, for example, an image processing unit or a position information calculation processing unit. This block is realized by the CPU operating by a predetermined program, for example. Other hardware and software may be used as appropriate to execute these processes.

  An image of another alignment mark B on the screen 5 side is taken. Based on the predetermined coordinate information, the camera unit is moved to the photographing position for photographing the alignment mark B (step 106).

  An alignment mark B is photographed (step 107). In the present embodiment, the illumination of the oblique illumination is continued from the time of photographing the alignment mark A. Therefore, when the camera unit 58 is moved, the photographing process is executed as it is. The illumination may be turned off when the alignment mark A is photographed. Then, when the camera unit 58 is moved, the illumination light L1 may be emitted from the plurality of light sources 75 again.

  Image processing is performed on the captured image of the screen 5, and the alignment mark B is detected (step 108). Thereby, for example, position information of the alignment mark B with respect to a predetermined photographing position is calculated.

  The emission of the illumination light L1 by the plurality of light sources 75 is stopped, and the oblique illumination is turned off (step 109). Then, in preparation for the photographing process of the circuit board W shown in FIG. 7, the second shutter 73 is closed as shown in FIG. Thereby, the second shutter 73 is disposed on the illumination optical axis L. The first shutter 79 is opened. Accordingly, the first shutter 79 is moved in the Y-axis direction (along arrow A) so that the illumination light L1 from the plurality of light sources 75 is emitted to the circuit board W (step 110).

  If it is determined in step 101 that the image of the alignment mark on the screen side has already been captured (Yes in step 101), the process proceeds to the imaging process of the circuit board W shown in FIG.

  A photographing process of the circuit board W shown in FIG. 7 will be described. First, the camera unit 58 is moved to a position waiting for the circuit board (step 201). The standby position is a position that does not hinder the conveyance of the circuit board W. For example, as shown in FIG. 1, the carriage 13 is positioned at the right end of the guide rail 11, and the camera unit 58 is moved to the back side in the X-axis direction at that position. This may be set as the standby position. The standby position may be set arbitrarily.

  The circuit board W is carried in by a conveyor or the like and placed on the placing table 32 (step 202). The outer shape of the circuit board W is clamped by the clamp mechanism 31. Thereby, the circuit board W is fixed (step 203).

  The camera unit 58 is moved to an imaging position for imaging one of the two alignment marks on the circuit board W side (described as alignment mark A) (step 204). This is executed based on preset coordinate information.

  As shown in FIG. 9A, illumination light L1 is emitted from a plurality of light sources 75 that realize oblique illumination. Since the first shutter 79 is opened, the illumination light L1 is emitted toward the circuit board W. The second reflected light L4 from the circuit board W illuminated obliquely enters the half mirror 83 along the illumination optical axis L. The second reflected light L4 is reflected in the direction opposite to the first reflected light L3 in the direction of the photographing optical axis P by the half mirror 83. Therefore, the second reflected light L4 is reflected to the reflecting plate 84.

  As shown in FIG. 9B, the reflecting plate 84 reflects the second reflected light L4 reflected by the half mirror 83 onto the imaging optical axis P toward the imaging device 60. As a result, the circuit board W is photographed and an image of the alignment mark A is photographed (step 205). The circuit board W is photographed by oblique illumination.

  Image processing is performed on the captured image of the circuit board W, and the alignment mark A is detected (step 206). Thereby, for example, position information of the alignment mark A with respect to a predetermined photographing position is calculated.

  As shown in FIG. 9A, the second reflected light L5 transmitted through the half mirror 83 is absorbed by the second shutter 73 that is closed. Therefore, for example, it is possible to prevent the screen 5 from being irradiated with the second reflected light L5 transmitted through the half mirror 83 and the reflected light being reflected on the photographing optical axis P. Moreover, the influence of external light can be prevented by closing the second shutter 73. As a result, the circuit board W can be clearly photographed.

  An image of another alignment mark B on the circuit board W side is taken. Based on the predetermined coordinate information, the camera unit 58 is moved to the shooting position for shooting the alignment mark B (step 207).

  An alignment mark B is photographed (step 208). The lighting of the oblique illumination may be continued, or may be turned on and off every time the alignment mark is photographed.

  Image processing is performed on the captured image of the circuit board W, and the alignment mark B is detected (step 209). Thereby, for example, position information of the alignment mark B with respect to a predetermined photographing position is calculated.

  The relative positions of the screen 5 and the circuit board W are adjusted based on the images of the screen 5 and the circuit board W taken by the imaging device 60. That is, the positional information on the alignment marks A and B on the circuit board W and the positional information on the alignment marks A and B on the screen 5 are referred to. Then, the alignment between the screen 5 and the circuit board W is corrected so that the coordinates of the respective alignment marks coincide (step 210). In this way, the alignment method according to the present embodiment is executed.

  The alignment correction may be performed, for example, by adjusting the position of the screen 5. That is, the screen support mechanism 6 that supports the screen 5 shown in FIG. 1 may have a function of adjusting the position of the screen 5. The screen support mechanism 6 may correct the alignment of the screen 5. Alternatively, an adjustment mechanism that can correct the position of the screen support mechanism 6 itself may be provided.

  The alignment between the screen 5 and the circuit board W may be corrected by moving the mounting table 32 by the drive unit 33 shown in FIG. In addition, a mechanism or a method for adjusting the relative position between the screen 5 and the circuit board W may be appropriately employed.

  The screen 5 is placed on the circuit board W at the adjusted position. In the present embodiment, the drive unit 33 raises and lowers the mounting table 32 in the Z-axis direction. As a result, the circuit board W placed on the stage 32 comes into contact with the screen 5. As a result, the screen 5 is placed on the circuit board W (step 211). A method of lowering the screen 5 and placing it on the circuit board W may be used.

  Screen printing is executed (step 212). That is, paste solder is supplied onto the screen 5 placed on the circuit board W at the adjusted position. The squeegee 21 is appropriately driven, and solder is printed on the circuit board W in a predetermined pattern.

  The drive unit 33 lowers the mounting table 32 in the Z-axis direction. Then, the circuit board W is discharged by a conveyor or the like (step 213).

  FIG. 10 is a flowchart illustrating an example of a board mounting process in which electronic components are mounted on the circuit board W. As shown below, an electronic component or the like is mounted on the circuit board W on which the solder is printed by the solder printing apparatus 100. Thereby, the circuit board W on which the electronic component is mounted is manufactured.

  A solder printing process is executed by the solder printing apparatus 100 (step 301). It is determined whether or not to inspect after solder printing (step 302). The determination process is determined based on, for example, a user instruction. Alternatively, the determination is made based on various conditions such as the type of component to be mounted, the pattern of solder printed on the circuit board W, the number of circuit boards W printed with solder, and the like. This condition may be input by the user. The conditions that are the criteria for the determination process are not limited.

  When it is determined that the inspection is executed after the solder printing (Yes in Step 302), the solder printed on the circuit board W is inspected (Step 303). For example, it is inspected whether solder is properly printed on the land of the circuit board W. It is inspected whether the solder does not protrude from the land, or there is no portion where the solder is insufficient. Thereby, it is determined whether the solder is properly printed in a predetermined pattern.

  The determination process may be performed by an inspection unit (not shown) provided in the solder printing apparatus 100. Alternatively, an inspection apparatus provided separately from the solder printing apparatus 100 may be used. For example, a circuit board W on which solder is printed is photographed, and an inspection is performed based on the image. In addition, any inspection method can be adopted.

  When the solder inspection is executed in step 303, the process proceeds to step 304. If it is determined in step 302 that the inspection after printing is not executed, the process also proceeds to step 304.

  In step 304, a component mounting process is performed by the component mounting apparatus. For example, the circuit board W on which the solder is printed by the solder printing apparatus 100 is carried into the component mounting apparatus. Various electronic components housed in a tape carrier or the like mounted on the component mounting apparatus are sucked up by a nozzle or the like. The nozzle that sucks the electronic component moves onto the circuit board W and places the electronic component at a predetermined position. The configuration and operation of the component mounting apparatus, the electronic component mounting method, and the like are not limited.

  In a state where the electronic component is placed at a predetermined position on the circuit board W, the solder is heated by reflow (step 305). For example, the circuit board W is carried into a reflow furnace and preheated, and then superheated. As a result, the solder is melted. Thereafter, a cooling process is performed, and the electronic component is bonded to the circuit board W.

  The circuit board W after the reflow process is inspected by the inspection apparatus (step 306). For example, it is inspected whether the electronic component is sufficiently adhered to a predetermined position. An imaging device for imaging the circuit board W after reflow, a sensor for detecting the position and height of the mounted electronic component, and the like may be used as appropriate.

  Visual inspection is also performed (step 307). In this way, the electronic component mounting process is performed, and the circuit board W is manufactured. In this way, the substrate manufacturing method according to the present embodiment is executed.

  As described above, in the illumination device 70 and the solder printing apparatus 100 according to the present embodiment, the illumination light 72 is emitted from the illumination unit 72 onto the illumination optical axis L to the screen 5. A half mirror 83 is disposed on the illumination optical axis L. The half mirror 83 transmits the illumination light L1 emitted from the illumination unit 72. Further, the first reflected light L3 that is reflected from the screen 5 irradiated by the transmitted illumination light L2 and is coaxial with the illumination optical axis L is on the photographing optical axis P of the imaging device 60 that photographs the screen 5. Reflected. Thereby, the screen 5 is coaxially illuminated. As a result, for example, it is possible to clearly photograph an alignment mark or the like provided on the screen 5 or the like.

  Here, photographing the screen 5 with coaxial epi-illumination will be described. In general, a through hole is often formed as an alignment mark for a screen, but recently, a marking type alignment mark is also increasing. If the stamped alignment mark is photographed by oblique illumination, the detection of the edge of the alignment mark may become unclear.

  Depending on the screen manufacturer, a screen whose surface is close to a mirror surface is manufactured. When such a screen is photographed with oblique illumination, for example, an image of the illumination itself may appear on the object. Then, there may occur a problem that the contrast necessary for detecting the alignment mark cannot be obtained.

  FIG. 11 is a schematic diagram and a photograph for specifically explaining a problem in photographing a screen whose surface is close to a mirror surface. FIG. 11A is a diagram of a lighting unit 500 used for photographing a screen. The illumination unit 500 includes a support substrate 501 having a circular shape and an imaging hole 502 formed at the center of the support substrate 501. The imaging hole 502 is a hole through which the imaging optical axis passes. That is, the light passing through the photographing hole is incident on the imaging device and the screen is photographed.

  The illumination unit 500 includes a plurality of light sources 503 formed around the imaging hole 502. The light source 503 is provided substantially perpendicular to the support substrate 501. Accordingly, illumination light from the plurality of light sources 501 is emitted in a direction substantially perpendicular to the support substrate 501.

  Such an illumination unit 500 is arranged in front of a screen whose surface is close to a mirror surface so that a plurality of light sources 501 face the screen. Illumination light is emitted from the plurality of light sources 501 to the screen, and the reflected light is photographed through the photographing hole 502.

  Then, as shown in the photograph of FIG. 11 (B), the central portion O of the image, which is the portion corresponding to the shooting hole 502, becomes dark and unevenness occurs in the image. This is considered to be due to the fact that the regular reflection component from the screen is strong and the illumination light from the plurality of light sources 503 cannot be spread. When unevenness occurs in the image, image recognition becomes difficult and alignment mark recognition becomes difficult.

  Thus, when photographing a screen or the like whose surface is close to a mirror surface, coaxial epi-illumination is more advantageous than oblique illumination. This will be described again by focusing on the regular reflectance and diffuse reflectance of the subject. 12 and 13 are schematic diagrams for explanation.

  A screen with a surface close to a mirror surface or a screen formed of a highly reflective metal such as stainless steel has a high regular reflectance (for example, about 55 to 88%) and a diffuse reflectance depending on the surface roughness. Low (eg about 8-10%). On the other hand, the resist formed on the substrate (including the circuit board W of the present embodiment) has a low regular reflectance (for example, 3 to 10%) and a high diffuse reflectance (for example, about 50% or more). The portion of the substrate to be plated has a regular reflectance of about 60%.

  Here, referring to FIG. 12, a case is considered where the photographing optical axis 602 of the camera 601 and the illumination optical axis 603 from the illumination are not coaxial, and the illumination light 604 is irradiated at a slight angle. In this case, as shown in FIG. 12A, the diffused light 605 of the diffuse reflection component D with respect to the illumination light 604 is incident on the camera 601 on the substrate surface 605 having a high diffuse reflectance. Further, the light of the regular reflection component M with respect to the illumination light 604 does not enter the camera.

  On the other hand, as shown in FIG. 12B, most components of the illumination light 604 are regularly reflected on the screen 610 having a low diffuse reflectance, and no light enters the camera 601. Even when light of the specular reflection component M enters the camera 601, the luminance difference from the diffuse reflection component D becomes large, and the function as illumination is impaired.

  As shown in FIG. 13, the regular reflection component M increases as the incident angle θ increases (see incident angles θ1 to θ3). For this reason, it is preferable that the illumination optical axis 603 for a screen or mirror surface with a high regular reflectance is arranged coaxially with the imaging optical axis 602 of the camera 601.

  In response to this, it is considered to shoot the screen 5 with coaxial epi-illumination. FIG. 14 is a schematic diagram showing a configuration of a general illumination unit 700 for realizing coaxial epi-illumination. In the illumination unit 700, a half mirror 703 is disposed on a photographing optical axis 702 that linearly extends toward the subject 701.

  Illumination light 705 is emitted from the light source 704 in a direction perpendicular to the photographing optical axis 702. The illumination light 705 is emitted toward the half mirror 703. The illumination light 705 is reflected on the photographing optical axis 702 by the half mirror 703 and is irradiated onto the subject 701. Reflected light from the subject 701 passes through the half mirror 703 and enters the camera 706 on the photographing optical axis 702. Thereby, coaxial epi-illumination is realized.

  When the lighting unit 700 having such a configuration is employed, the lighting unit 700 is disposed, for example, below the main body 71 shown in FIG. However, it is difficult to secure a space for arranging the lighting unit 700. Further, the cost may increase due to an increase in the number of necessary parts and the necessity of adjusting the optical axis of the mirror. In addition, the lighting circuit and wiring may be complicated. Furthermore, since it is necessary to take a long optical path in order to eliminate unevenness of the light source, there is a problem that the size increases.

  Therefore, for example, it is also considered to realize a coaxial epi-illumination in a pseudo manner. The pseudo coaxial epi-illumination is illumination that irradiates the screen with illumination light that is not coaxial with the photographing optical axis but is parallel to the photographing optical axis from near the photographing optical axis. FIG. 15 is a schematic diagram illustrating a configuration example for realizing pseudo coaxial epi-illumination.

  FIG. 15A is a schematic diagram illustrating an example of an illumination unit that realizes pseudo coaxial epi-illumination. In the illumination unit 800, the size of the photographing hole 802 formed in the center of the support substrate 801 is smaller than the photographing hole 502 shown in FIG. A plurality of light sources 803 are provided around the photographing hole 802. The plurality of light sources 803 are provided close to the imaging hole 802. The plurality of light sources 803 are also arranged on a substantially concentric circle with the photographing hole 802 as the center. With such a configuration, pseudo coaxial epi-illumination is realized.

  Such a lighting unit 800 is arranged in front of the screen whose surface is close to a mirror surface so that a plurality of light sources 803 face the screen. Illumination light is emitted from a plurality of light sources 803 to the screen, and the reflected light is photographed through the photographing hole 802.

  Even in such a pseudo coaxial epi-illumination, as shown in FIG. 15B, the central portion O of the image corresponding to the imaging hole 802 becomes dark and unevenness occurs. . As a result, alignment mark recognition becomes difficult. For example, when the area of the photographing hole 802 becomes large, unevenness of the photographed image becomes a problem.

  The present technology has been devised for such problems. That is, in the illumination device 70 according to the present embodiment, a plurality of light sources 75 are provided on the opposite side of the screen 5 of the support portion 76 disposed at a position facing the screen 5. Illumination light L1 emitted from the plurality of light sources 75 is reflected by the reflection surface 78 of the first shutter 79. The reflected illumination light L 1 is irradiated onto the illumination optical axis L through an opening 77 formed in the support portion 76. Thereby, unnecessary light such as external light can be prevented, and illumination light L1 from a plurality of light sources 75 can be accurately irradiated onto the illumination optical axis L.

  According to the illumination device 70 and the solder printing apparatus 100 according to the embodiment of the present technology, it is possible to realize a small camera unit 58 that fits in a space between the screen 5 and the circuit board W. Further, coaxial incident illumination can be realized for the screen 5. As a result, even when a screen 5 having a high regular reflectance is used, it is possible to clearly photograph the alignment mark formed on the screen 5 by engraving or the like.

  In addition, the space for realizing the coaxial drop illumination is small, and the number of necessary parts can be reduced. As a result, the cost can be reduced. Moreover, since the structure of the illumination part 72 is simple, it can prevent that an illumination circuit, wiring, etc. become complicated.

  In the illumination device 70 according to the present embodiment, the optical distance of the illumination light L1 emitted from the plurality of light sources 75 can be increased. That is, the optical distance can be made larger than when the light source is arranged in front of the screen 5. As a result, it becomes possible to irradiate the screen 5 with the illumination light L1 whose natural diffusion has progressed and whose luminance is uniform. Therefore, for example, it is not necessary to add parts such as a diffusion plate, and the cost can be suppressed. For example, when the distance from the screen 5 to the circuit board W is 100 mm, the optical path length of the illumination light is about 90 mm.

  It is not necessary to prepare a light source for photographing the screen 5 and a light source for photographing the circuit board W, and both can be photographed using the light source 75. Accordingly, the configuration of the illumination device 70 is simplified, and the camera unit 58 can be downsized.

  Since there is no illumination on the screen 5 side, when the cream solder falls from the screen 5, the illumination substrate is not damaged by the solder.

  By connecting the illumination device of the present embodiment, it is possible to photograph the screen 5 and the circuit board W by appropriately moving the imaging device 60 in a state where the photographing optical axis P is parallel to the screen 5. .

  In the present lighting device 70, the first shutter 79 is provided so as to be movable. As the first shutter 79 moves, the illumination light L1 from the light source 75 is irradiated onto the circuit board W facing the screen 5 in the direction of the illumination optical axis L. The second reflected light L4 from the circuit board W is irradiated onto the photographing optical axis P through the half mirror 83 and the reflecting plate 84. In this way, the screen 5 and the circuit board W can be appropriately photographed by the illumination light L1 from the plurality of light sources 75.

  In the illumination device 70, even when the screen 5 having a large regular reflectance is used, the screen 5 is coaxially illuminated by the illumination unit 72. The circuit board W having a small regular reflectance is illuminated obliquely. As a result, the screen 5 and the circuit board W are clearly photographed.

<Modification>
The embodiment according to the present technology is not limited to the embodiment described above, and various modifications are made.

  For example, FIG. 16 is a schematic diagram illustrating a modification of the illumination device 70 illustrated in FIG. 3. In the lighting device 270, an auxiliary lighting unit 290 is provided on the upper portion of the main body 71. The auxiliary illumination unit 290 is disposed between the main body 271 and the second shutter 273 (closed state).

  The auxiliary illumination unit 290 includes an auxiliary support unit 276 disposed between the half mirror 283 and the screen 5, an auxiliary opening 277 through which the illumination optical axis L formed in the auxiliary support unit 276 passes, and around the auxiliary opening 277. And one or more auxiliary light sources 275 that irradiate the screen 5 with the auxiliary illumination light L6.

  The auxiliary illumination unit 290 is disposed in order to clarify the image of the screen 5 photographed with the coaxial incident illumination. For example, in the image of the screen 5 photographed with coaxial epi-illumination, the edge portion may become darker than the center portion. Accordingly, by irradiating the screen 5 with the auxiliary illumination light L6 from the auxiliary light source 275, it is possible to capture an image with high overall brightness. As a result, a clear image of the screen 5 can be taken, and the alignment mark can be recognized with high accuracy. In addition, the assistance of the amount of light applied to the screen 5 may be performed as appropriate.

  The auxiliary illumination unit 290 has a configuration substantially similar to that of the illumination unit 72 illustrated in FIG. 4, for example. The shape and size of the auxiliary support part 276 and the auxiliary opening 277 can be set as appropriate. The number and position of the plurality of auxiliary light sources 275 can also be set. For example, the plurality of auxiliary light sources 275 may be provided at such an angle that the auxiliary illumination light L6 is irradiated around the position where the illumination optical axis L intersects the screen 5. Any other configuration can be adopted.

  In the above, a screen having a high regular reflectance and a circuit board having a low regular reflectance were photographed by the camera unit. However, the camera unit may be used for the purpose of photographing only a subject with high regular reflectance (in this case, a screen) with coaxial incident illumination. In this case, the second shutter is not provided, and a member that absorbs light may be used instead of the reflector of the illumination optical system. As a result, a subject located on the opposite side of the illumination unit can be clearly photographed. Such a camera unit may be used as the camera unit according to the present embodiment.

  In the above, a half mirror is used as a semitransparent mirror. In addition, a semi-transparent prism may be used as a semi-transparent mirror. As the semi-transparent prism, for example, two rectangular prisms bonded together and a dielectric multilayer film or a metal thin film coated on the joint surface may be used. When a half mirror is used, there is a possibility that the influence of the thickness of the half mirror may occur. In such a case, highly accurate coaxial epi-illumination can be achieved by using a translucent prism.

  Surface treatment may be appropriately performed on the reflective surface of the first shutter. For example, by performing white coating on the reflecting surface, it is possible to improve the diffusion effect of illumination light and reduce luminance unevenness.

  In the above, paste solder is screen-printed on the circuit board W. However, a conductor paste other than solder or a resistor paste may be used as the paste material. Even when such a paste material is screen-printed, the illumination device 70 according to the present embodiment can be used.

  The entire camera unit 58 shown in FIG. 3 may be used as the imaging apparatus according to the present embodiment. In this case, the imaging device 60 shown in the figure functions as an imaging unit according to the present embodiment.

  In the above, the illumination unit is provided on the opposite side of the subject with respect to the main body so that the subject having a high regular reflectance is coaxially illuminated. Therefore, for example, when the regular reflectance of the circuit board is higher than that of the screen, it is only necessary to take an image with the camera unit upside down.

  In the above, the illumination optical axis L is perpendicular to the screen 5. However, the range is not limited to the vertical direction as long as the coaxial epi-illumination is possible.

  In the above, the screen is exemplified as the first subject, and the circuit board is exemplified as the second subject. However, the present invention is not limited to photographing these members. For example, when photographing two members facing each other in a small space, the lighting device according to the present technology can be used. When one of the two members is a member having a high regular reflectance, the subject can be clearly photographed by photographing the subject with coaxial epi-illumination.

  In addition, this technique can also take the following structures.

(1) an illumination unit that includes one or more light sources that emit illumination light to the first subject, and that irradiates illumination light from the light source onto an illumination optical axis to the first subject;
A first light beam arranged on the illumination optical axis, transmits the illumination light irradiated by the illumination unit, and is coaxial with the illumination optical axis from the first subject irradiated by the transmitted illumination light. An illumination device comprising: a translucent mirror that reflects reflected light on a photographing optical axis of an imaging device that photographs the first subject.
(2) The illumination device according to (1),
The illumination device, wherein the illumination optical axis is perpendicular to the first subject.
(3) The illumination device according to (1) or (2),
The illumination unit includes a support unit disposed at a position facing the first subject, an opening formed in the support unit through which the illumination optical axis passes, and a side of the support unit opposite to the first subject. An illumination device comprising: a plurality of light sources provided around the opening; and a first shutter having a reflective surface that reflects the illumination light from the plurality of light sources to the opening.
(4) The illumination device according to (2) or (3),
And further comprising a connecting portion for connecting the illumination device to the imaging device such that the imaging optical axis of the imaging device is orthogonal to the illumination optical axis,
The translucent mirror reflects the first reflected light on the photographing optical axis by reflecting the first reflected light from the first subject at a right angle.
(5) The illumination device according to (3) or (4),
The first shutter is movable so that illumination light from the light source is irradiated to a second subject facing the first subject in the direction of the illumination optical axis,
The translucent mirror reflects the second reflected light from the second subject irradiated with the illumination light in a direction opposite to the first reflected light in the direction of the photographing optical axis,
The illuminating device further includes a reflection unit configured to reflect the second reflected light reflected by the translucent mirror on the photographing optical axis.
(6) The illumination device according to (5),
A second shutter that is disposed on the photographing optical axis between the translucent mirror and the first subject and absorbs the second reflected light from the second subject that passes through the translucent mirror. An illumination device further comprising:
(7) The illumination device according to any one of (1) to (6),
An auxiliary support portion disposed between the translucent mirror and the first object, an auxiliary opening formed in the auxiliary support portion through which the illumination optical axis passes, and provided around the auxiliary opening. An illuminating device further comprising an auxiliary illuminating unit having one or more auxiliary light sources that irradiate auxiliary light to one subject.
(8) The illumination device according to any one of (5) to (7),
The illuminating device, wherein the regular reflectance of the first subject is larger than the regular reflectance of the second subject.
(9) The illumination device according to any one of (5) to (7),
The first subject is a screen for printing a paste material;
The second object is a lighting object on which the paste material is printed using the screen.

W ... Circuit board P ... Imaging optical axis L ... Illumination optical axis L1, L2 ... Illumination light L3 ... First reflected light L4, L5 ... Second reflected light L6 ... Auxiliary illumination light 5 ... Screen 58 ... Camera unit 60 ... Imaging device 70 ... Illuminating device 71 ... Main body 72 ... Illuminating unit 73 ... Second shutter 74 ... Illuminating optical system 75 ... Light source 76 ... Supporting unit 77 ... Opening 78 ... Reflecting surface 79 ... First shutter 83 ... Half mirror 84 ... Reflector 100 ... Solder printer 270 ... Illuminator 271 ... Main body 273 ... Second shutter 275 ... Auxiliary light source 276 ... Auxiliary support 277 ... Auxiliary opening 283 ... Half mirror 290 ... Auxiliary illumination

Claims (13)

1 and or more light sources for emitting irradiation Meiko, and a first shutter for reflecting the illumination light from the one or more light sources to the first object, the illumination light from the one or more light sources An illuminating unit that irradiates the illuminating optical axis onto the first subject by reflecting the first object with the first shutter ;
A first light beam arranged on the illumination optical axis, transmits the illumination light irradiated by the illumination unit, and is coaxial with the illumination optical axis from the first subject irradiated by the transmitted illumination light. An illumination device comprising: a translucent mirror that reflects reflected light on a photographing optical axis of an imaging device that photographs the first subject. The lighting device according to claim 1,
The illumination device, wherein the illumination optical axis is perpendicular to the first subject. The lighting device according to claim 1,
The illumination unit includes a support unit disposed at a position facing the first subject, an opening formed in the support unit through which the illumination optical axis passes, and a side of the support unit opposite to the first subject. illumination having a plurality of light sources for emitting the illumination light provided around the opening there is, and the first shutter having a reflective surface for reflecting the illumination light from the plurality of light sources to said opening apparatus. The lighting device according to claim 2,
And further comprising a connecting portion for connecting the illumination device to the imaging device such that the imaging optical axis of the imaging device is orthogonal to the illumination optical axis,
The translucent mirror reflects the first reflected light on the photographing optical axis by reflecting the first reflected light from the first subject at a right angle. The lighting device according to claim 3,
The first shutter is movable so that illumination light from the light source is irradiated to a second subject facing the first subject in the direction of the illumination optical axis,
The translucent mirror reflects the second reflected light from the second subject irradiated with the illumination light in a direction opposite to the first reflected light in the direction of the photographing optical axis,
The illuminating device further includes a reflection unit configured to reflect the second reflected light reflected by the translucent mirror on the photographing optical axis. The lighting device according to claim 5,
A second shutter that is disposed on the photographing optical axis between the translucent mirror and the first subject and absorbs the second reflected light from the second subject that passes through the translucent mirror. An illumination device further comprising: The lighting device according to claim 1,
An auxiliary support portion disposed between the translucent mirror and the first object, an auxiliary opening formed in the auxiliary support portion through which the illumination optical axis passes, and provided around the auxiliary opening. An illuminating apparatus further comprising an auxiliary illuminating unit including one or more auxiliary light sources that irradiate one subject with auxiliary illumination light. The lighting device according to claim 5,
The illuminating device, wherein the regular reflectance of the first subject is larger than the regular reflectance of the second subject. The lighting device according to claim 5,
The first subject is a screen for printing a paste material;
The second object is a lighting object on which the paste material is printed using the screen. An imaging unit for photographing a subject;
1 and or more light sources for emitting irradiation Meiko, the illumination light from the one or more light sources and a shutter for reflecting the object, reflected by the shutter of the illumination light from the one or more light sources an illumination unit for irradiating the illumination optical axis to the object by,
The reflected light that is arranged on the illumination optical axis, transmits the illumination light irradiated by the illumination unit, and is coaxial with the illumination optical axis from the subject irradiated by the transmitted illumination light is imaged An imaging device comprising: a translucent mirror that reflects on the photographing optical axis of the part. An imaging unit capable of photographing each of the screen and a printing object facing the screen;
A support portion disposed between the screen and the print object;
An opening formed in the support portion through which an illumination optical axis to the screen parallel to a direction in which the screen and the printing object are opposed to each other;
A plurality of light sources provided on the print object side of the support and around the opening;
An illumination unit that includes a shutter that has a reflecting surface that reflects the illumination light from the plurality of light sources to the opening and is movable when illumination light from the plurality of light sources is irradiated on the print target; ,
The illumination optical axis from the screen that is disposed on the illumination optical axis between the illumination unit and the screen, transmits the illumination light irradiated by the illumination unit, and is irradiated by the transmitted illumination light. The first reflected light that is coaxial is reflected on the photographing optical axis of the imaging unit, and the second reflected light from the printing object irradiated with the illumination light by the movement of the shutter is the photographing light. A translucent mirror that reflects in a direction opposite to the first reflected light in an axial direction;
An optical system comprising: a reflecting portion that reflects the second reflected light reflected by the semi-transparent mirror onto the photographing optical axis;
The relative position between the screen and the printing object is adjusted based on the images of the screen and the printing object photographed by the imaging unit, and the printing object is adjusted at the adjusted position. A screen printing apparatus comprising: a screen printing unit configured to supply a paste material onto the screen placed on the screen and print the supplied paste material on the print object. Illumination light emitted from one or more light sources toward the second subject between the first subject and the second subject facing the first subject is used as the one or more light sources and the first subject. A reflection surface of a shutter disposed between the two subjects and reflecting the first subject to irradiate the illumination light on the illumination optical axis to the first subject,
The translucent mirror disposed on the illumination optical axis transmits the illumination light irradiated on the illumination optical axis and is coaxial with the illumination optical axis from the first subject irradiated by the transmitted illumination light. The first reflected light is reflected on the imaging optical axis of an imaging device that images the first subject, and the first subject is captured,
Illuminating the second subject with illumination light from the one or more light sources by moving the shutter;
The semi-transparent mirror reflects the second reflected light from the second subject irradiated with the illumination light in a direction opposite to the first reflected light in the direction of the photographing optical axis,
Reflecting the second reflected light reflected by the translucent mirror on the photographing optical axis by a reflecting unit, photographing the second subject,
A positioning method that adjusts relative positions of the first and second subjects based on respective images of the first and second subjects photographed by the imaging device. Illumination light emitted from one or more light sources toward the substrate between the screen and the substrate facing the screen is reflected on a reflection surface of a shutter disposed between the one or more light sources and the substrate. Irradiating the illumination light on the illumination optical axis to the screen
A translucent mirror disposed on the illumination optical axis transmits the illumination light irradiated on the illumination optical axis, and is coaxial with the illumination optical axis from the screen irradiated by the transmitted illumination light. The reflected light of 1 is reflected on the photographing optical axis of the imaging device that photographs the screen, and the screen is photographed.
Irradiating the substrate with illumination light from the one or more light sources by moving the shutter;
The semi-transparent mirror reflects the second reflected light from the substrate irradiated with the illumination light in the direction opposite to the first reflected light in the direction of the photographing optical axis,
Reflecting the second reflected light reflected by the semi-transparent mirror on the imaging optical axis by a reflection unit, imaging the substrate,
The relative positions of the screen and the substrate are adjusted based on the images of the screen and the substrate taken by the imaging device, and the screen is placed on the substrate at the adjusted position. Then, a paste material is printed on the substrate by screen printing, and a component is mounted on the substrate on which the paste material is printed.