JP2013016570A - Laser height measuring apparatus and component mounting machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser height measuring apparatus that accurately controls a measuring position, and maintains control precision of the measuring position without requiring a sensor mounting position adjustment mechanism nor a position adjustment operation.SOLUTION: A laser height measuring apparatus includes: a laser height sensor 6 having a laser light radiation section 61 for radiating laser light L1 and a reflected light detection section 62 for detecting laser light reflected by an object; a sensor moving mechanism (head drive mechanism 41-43) for moving the laser height sensor 6 in a plane; an image camera (component camera 5) arranged in a predetermined calibrating position (on a light incidence axis AO); a neutral density filter 71 for attenuating and transmitting the laser light L1; laser light imaging means for positioning the laser height sensor 6 at the calibrating position AO, radiating the laser light L1 and imaging laser light transmitted through the neutral density filter 71 by means of the image camera 5 to obtain a laser light image; and correction value acquisition means for determining a value for correcting a coordinate position on the basis of the position of the laser light on the laser light image.

Description

  The present invention relates to a laser height measuring device that measures the height of an object using laser light, and a component mounting machine that measures the upper surface height of a substrate by incorporating the laser height measuring device, and more particularly The present invention relates to a measuring position correcting means for measuring height.

  There are solder printing machines, component mounting machines, reflow machines, board inspection machines, etc., as board production machines that perform production operations on boards, and it is common to build a board production line by connecting these with a board transfer device It has become. Among these, the component mounter is a substrate transfer device that loads, positions, and unloads a board at a component mounting position, a component supply device that supplies components, and a component that is picked up from the component supply device and mounted on a positioned substrate A component transfer device having a head drive mechanism for driving the head and the mounting head in two orthogonal directions in a horizontal plane; and a component camera for imaging a component collected while the mounting head moves from the component supply device onto the substrate; It is equipped with. The component mounter further includes a board camera in the mounting head in order to confirm the position of the positioned board, the ID code, and the like.

  In recent years, a technique has been proposed in which a laser height sensor is attached to a mounting head of a component mounting machine and moved to a predetermined coordinate position of the board positioned by a head driving mechanism, and the board height is measured at a plurality of positions. As a result, the height of the upper surface of the substrate on which the component is mounted can be accurately measured, and an effect of performing a smooth component mounting operation even if the substrate is warped or the like is produced. The laser height sensor is not limited to a component mounting machine, and is applied to a board inspection machine as exemplified in Patent Document 1. The substrate inspection apparatus of Patent Document 1 includes a laser displacement sensor (laser height sensor), a displacement measurement unit, a measurement position teaching unit, and a substrate height calculation unit, and performs inspection by obtaining the height of an inspection target on the substrate. To do.

  The laser height sensor attached to the mounting head of the component mounting machine is driven in two orthogonal directions in the horizontal plane by the head driving mechanism, and the measurement position is controlled using the coordinate values of the plane coordinate system on the head driving mechanism. . The positional relationship of the mounting head with respect to the component mounting machine base causes structural dimensional errors due to dimensional tolerances of components and variations in mounting and adjustment. Therefore, position correction is performed using the above-described imaging data of the board camera. Has become commonplace. This position correction also eliminates the positional relationship error with respect to the mounting head of the board camera. Further, this position correction is similarly applied to the correction of the measurement position of the laser height sensor.

  On the other hand, the height measurement accuracy of the laser height sensor tends to depend on the surface state of the substrate that is the object. For example, if the height is not constant within the area range required for measurement, the height measurement accuracy is lowered. Further, the reflectance of the laser beam varies depending on the surface material, and the reflectance of the land pattern is high. However, the reflectance of the substrate substrate is low, which may be a cause of a decrease in height measurement accuracy. For example, even if the measurement position is set within a predetermined marker or land pattern, the height measurement accuracy decreases if the irradiation position of the laser beam protrudes from the marker or land pattern during actual measurement due to a control error of the measurement position. Patent examples 2 and 3 disclose technical examples related to this type of height measurement accuracy improvement.

  The three-dimensional shape measuring apparatus of Patent Literature 2 includes a line sensor that reads an optical pattern whose luminance periodically changes according to the position as an image, and one of the line sensor and the measurement target that is different from the main scanning direction of the line sensor. A moving unit that moves in a direction and an image analysis unit that controls the moving unit and analyzes the image to measure the three-dimensional shape of the measurement target are provided. The image analysis unit performs calibration using a calibration target having a plurality of heights, for example, a calibration target having three or more flat surfaces. Thus, it is not necessary to replace the calibration target or adjust the height, and the height calibration can be performed quickly.

  Further, the laser light amount control device disclosed in Patent Document 3 includes a laser light source that emits laser light, a condensing lens that condenses and emits the laser light, and detection means that detects monitor light obtained by separating a part of the laser light. And a light amount control means for controlling the light amount of the laser light based on the light amount of the monitor light, and the condensing lens has a reflection surface that reflects a part of the laser light as the monitor light. Further, in the embodiment, a photodiode is exemplified as the monitor light detection means. According to this configuration, highly stable monitor light can be obtained without using expensive parts such as a beam splitter, and the apparatus can be reduced in size and cost.

  In addition, the technique of the height measurement by a laser height sensor is not limited to a substrate production machine, but is a technique that can be applied to equipment machines in a wide range of fields.

JP 2005-30793 A JP 2008-170279 A JP 2003-110188 A

  By the way, in the configuration in which the laser height sensor and the board camera are incorporated in the mounting head of the component mounting machine, conventionally, the positional relationship of the mounting head with respect to the component mounting machine base has been calibrated by the imaging data of the board camera. For this reason, although the control accuracy of the component mounting point on the board and the imaging position is kept good, the control accuracy of the measurement position of the laser height sensor may be lowered. This is because when mounting the laser height sensor to the mounting head, there are dimensional tolerances of components and variations in mounting and adjustment, as in the case of the substrate camera, and errors in the positional relationship of the sensor with respect to the mounting head may occur. Nevertheless, calibration and correction are not performed. Therefore, in order to ensure the control accuracy of the measurement position of the laser height sensor, a sensor mounting position adjustment mechanism is provided, and the mounting position is adjusted individually by each component mounter. It was necessary to pay special attention to variations in adjustment work.

  On the other hand, in order to reduce the size of the substrate, components and circuit patterns have become lighter and thinner, and the mounting density of components has been increasing in recent years, and the measurement positions suitable for height measurement using a laser height sensor have been limited. That is, the measurement range in which the height is constant and the reflectance of the laser beam is good is limited, and the measurement range can be secured only less than about 1 mm square. For this reason, in order to improve the measurement height accuracy of the laser height sensor, it is an urgent task to improve the control accuracy of the measurement position.

  On the other hand, the techniques of Patent Documents 1 and 2 are techniques related to calibration and correction of the measurement height itself, and the technique of Patent Document 3 is a technique related to light amount adjustment of laser light used for measurement, both of which are measurement positions. It does not maintain or improve the control accuracy.

  The present invention has been made in view of the problems of the background art described above, and can accurately control the measurement position when measuring the height, and does not require a sensor attachment position adjustment mechanism or position adjustment work. It is an object to be solved to provide a laser height measuring device capable of maintaining the control accuracy of a measurement position, and a component mounting machine incorporating the laser height measuring device.

  The invention of the laser height measuring device according to claim 1 that solves the above-described problem includes a laser beam irradiation unit that irradiates a laser beam toward an object, and reflected light detection that detects the laser beam reflected by the object. A laser height sensor comprising: a laser height sensor that measures the height of the object, and a sensor moving mechanism that moves the laser height sensor in a plane, wherein the sensor movement An image camera arranged at a predetermined calibration position represented by a plane coordinate system on the mechanism, and a laser light irradiation part of the laser height sensor positioned at the calibration position and a light incident part of the image camera A neutral density filter that transmits and attenuates laser light emitted from the laser light irradiation unit toward the light incident unit; and the laser height sensor is positioned at the calibration position. A laser beam imaging unit that irradiates the laser beam from the laser beam irradiation unit toward the light incident unit and captures the laser beam transmitted through the neutral density filter with the image camera; The coordinate position in the plane coordinate system of the laser beam irradiated from the laser beam irradiation unit toward the object when the laser height sensor is moved to the coordinate position of the plane coordinate system by the sensor moving mechanism Correction value acquisition means for obtaining the correction value based on the position of the laser beam on the laser beam image.

  According to a second aspect of the present invention, in the first aspect, the laser height measuring device is incorporated in a board production machine that produces a board on which a component is mounted, and the object is a work position of the board production machine. The neutral density filter is disposed in a horizontal posture at the same height as the upper surface of the substrate clamped in the working position.

  According to a third aspect of the present invention, there is provided a component mounting machine including: a board conveying device that loads, positions, and unloads a substrate at a component mounting position; a component supply device that supplies a component; and the component is collected from the component supply device. A component transfer device having a mounting head to be mounted on the positioned substrate, and a head drive mechanism for driving the mounting head in two orthogonal directions in a horizontal plane, and the mounting head being moved from the component supply device onto the substrate A component camera that captures an image of the component picked up in step (1), wherein the laser height sensor of the laser height measuring device according to claim 1 or 2 is attached to the mounting head. The head driving mechanism is also used as the sensor moving mechanism of the laser height measuring device, and the component camera is also used as the image camera of the laser height measuring device. Is, the ND filter of the laser height measuring device, the the component camera of the light entrance portion on are arranged horizontally at the same height as the upper surface of the substrate positioned on the component mounting position.

  In the invention of the laser height measuring device according to the first aspect, the laser light is irradiated from the laser light irradiation portion of the laser height sensor positioned at the calibration position by the sensor moving mechanism, and the laser light attenuates the neutral density filter. It passes through and reaches the image camera, and a laser beam image is obtained. The position of the laser beam on the laser beam image can be obtained with high accuracy by the action of the neutral density filter, and the amount of deviation from the calibration position can be obtained as a correction value for the coordinate position. Thereby, when the laser height sensor is moved to an arbitrary coordinate position by the sensor moving mechanism, the irradiation position of the laser beam, that is, the measurement position can be corrected using this correction value. That is, when measuring the height at an arbitrary coordinate position, the measurement position can be accurately controlled by moving the laser height sensor in consideration of the correction value by the sensor moving mechanism.

  Further, even if a structural dimensional error due to a dimensional tolerance of sensor constituent members or a variation in mounting work occurs, the dimensional error can be obtained as a correction value for each measuring apparatus and can be corrected. Therefore, the control accuracy of the measurement position can be maintained without requiring a sensor attachment position adjustment mechanism or a position adjustment operation.

  In the invention according to claim 2, the laser height measuring device is incorporated in the substrate production machine, the object is a substrate clamped in a horizontal posture, and the neutral density filter is in a horizontal posture at the same height as the upper surface of the substrate. It is arranged with. For this reason, even if the laser height sensor is tilted and the optical axis of the laser beam is tilted, the error of the coordinate position on the neutral density filter at the calibration position and the error of the coordinate position on the upper surface of the substrate Are approximately the same. Therefore, any measurement position on the substrate can be accurately controlled by using the correction value obtained at the calibration position.

  In the invention of the component mounter according to claim 3, the laser height sensor is attached to the mounting head, the head drive mechanism is also used as the sensor moving mechanism, the component camera is also used as the image camera, and the neutral density filter is used as the component camera. A horizontal posture is arranged on the light incident part at the same height as the upper surface of the substrate. Therefore, a correction value can be obtained using a neutral density filter as a jig without changing the configuration of a conventional component mounting machine, and an arbitrary measurement position on the substrate can be accurately controlled. Thereby, the height of the upper surface of the board can be accurately measured at a plurality of positions, and a smooth component mounting operation can be performed even if the board is warped.

It is a perspective view explaining the component mounting machine of embodiment. (1) is a diagram for schematically explaining the configuration of the laser height sensor and the height detection method, and (2) is a diagram for schematically explaining the object and measurement position for height measurement. It is a figure explaining the calibration implementation situation of the measurement position of the laser height measuring device built in the component mounting machine of an embodiment. It is the fragmentary perspective view which expanded the range from the laser height sensor of FIG. 3 to a connection part. It is a perspective sectional view showing the structure of a calibration jig having a neutral density filter. It is an example of a laser beam image obtained in the embodiment, (1) shows an entire region image, and (2) shows an enlarged image of the central portion of (1). It is an example of a laser beam image obtained when a calibration jig is not used, (1) shows an entire region image, and (2) shows an enlarged image of the central portion of (1). It is another example of a laser beam image explaining the effect | action which a neutral density filter raises the position of the transmitted laser beam highly, (1) shows the time of using a neutral density filter, (2) shows the time of non-use of a neutral density filter. Yes.

  A component mounter according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view illustrating a component mounter 1 according to an embodiment. The component mounter 1 of the embodiment incorporates the laser height measuring device of the present invention. The component mounter 1 assembles the substrate transfer device 2, the component supply device 3, the component transfer device 4, and the component camera 5 on the base 9, and attaches the laser height sensor 6 to the mounting head 44 of the component transfer device 4. Attach and configure each device 2 to 6 to be controlled from a control computer (not shown).

  The substrate transfer device 2 includes first and second guide rails 21 and 22, a pair of conveyor belts, a clamp device, and the like. The first and second guide rails 21 and 22 are assembled to the base 9 so as to extend in the transport direction (X-axis direction) across the upper center of the base 9 and to be parallel to each other. A pair of conveyor belts arranged in parallel to each other are arranged directly below the first and second guide rails 21 and 22. The conveyor belt rotates in the conveyance direction (X direction) with the substrate K placed on the conveyor conveyance surface, and carries the substrate K to and from the component mounting position set at the center of the base 9. A clamping device is provided below the conveyor belt at the center of the base 9. The clamp device pushes up the substrate K, clamps it in a horizontal posture, and positions it at the component mounting position. FIG. 1 shows the substrate K positioned at the component mounting position.

  The component supply device 3 is a feeder-type device, and is provided at the front portion in the longitudinal direction of the component mounter 1 (left front side in FIG. 1). The component supply device 3 is configured with a large number of cassette-type feeders 31 that can be attached and detached. The cassette type feeder 31 includes a main body 32, a supply reel 33 provided at the rear part of the main body 32, and a component take-out part 34 provided at the tip of the main body 32. An elongated tape (not shown) in which a large number of parts are enclosed at a predetermined pitch is wound and held on the supply reel 33. This tape is pulled out at a predetermined pitch by a sprocket (not shown), and the part is released from the enclosed state. The components are sequentially fed into the component take-out unit 34.

  The component transfer device 4 is an XY robot type device that can move in the X-axis direction and the Y-axis direction. The component transfer device 4 includes a pair of Y-axis rails 41 and 42, a mounting head 44, a suction nozzle 45, a board camera 46, and the like. The pair of Y-axis rails 41 and 42 are arranged from the rear part in the longitudinal direction of the base 9 (the right back side in FIG. 1) to the upper part of the front part supply device 3. On the Y-axis rails 41 and 42, a moving table 43 is supported so as to be movable in two horizontal directions (XY directions). A mounting head 44 is provided on the movable table 43. The mounting head 44 is provided with a suction nozzle 45 that sucks and collects components by negative pressure, and a substrate camera 46 that images the upper surface of the substrate K.

  The mounting head 44 of the component transfer device 4 is driven in two horizontal directions (XY directions) by two servo motors, and the suction nozzle 45 is driven in the up-and-down direction by another servo motor. Thereby, the suction nozzle 45 picks up the component from the cassette type feeder 31 of the component supply device 3 and mounts it on the mounting point on the substrate K positioned. The board camera 46 reads the fiducial mark of the board K that has been positioned, detects a position error with respect to the component mounting position of the board K, and reflects the position error when the suction nozzle 45 mounts the component.

  The Y-axis rails 41 and 42, the moving table 43, and the two servo motors described above constitute a head drive mechanism that drives the mounting head 44 in two orthogonal directions within a horizontal plane. Further, the component mounting position and the mounting point are represented by coordinate values in a plane coordinate system on the head drive mechanism. The relative positional relationship of the mounting head 44 with respect to the base 9 is calibrated in advance by imaging data of the board camera 46 when the mounting head 44 is moved to a reference position expressed in a plane coordinate system. That is, a correction value to be applied at an arbitrary coordinate position in the plane coordinate system is obtained in advance. Therefore, even if a structural dimensional error occurs due to a dimensional tolerance of components constituting the mounting head 44 or the head driving mechanism or variations in mounting and adjustment, the position of the mounting head 44 can be controlled by using the correction value. The accuracy is kept good.

  The component camera 5 is provided upward on the upper surface of the base 9 between the substrate transfer device 2 and the component supply device 3. The component camera 5 captures and detects the state of a component that is picked up while the suction nozzle 45 moves from the component supply device 3 onto the substrate K. When the component camera 5 detects a component suction position, a rotation angle shift, a lead bend, or the like, the component mounting operation is finely adjusted as necessary, and components that are difficult to mount are discarded. The detailed structure around the component camera 5 will be described later.

  The component mounting machine 1 includes a control computer (not shown). The control computer is based on various information including the correspondence relationship between the board type of the board to be produced and the part type to be mounted, imaging data of the board camera 46 and the part camera 5, and detection information of a sensor (not shown). Control the component mounting operation.

  Next, a laser height measuring device will be described. As shown in FIG. 1, the laser height sensor 6 constituting the laser height measuring apparatus is attached to the lower side of the mounting head 44 side by side with the substrate camera 46. Therefore, the laser height sensor 6 is moved by the mounting head 44, and the head driving mechanism is also used as a sensor moving mechanism for moving the laser height sensor 6. (1) of FIG. 2 is a figure which illustrates typically the structure of the laser height sensor 6, and a height detection system, (2) is a figure which illustrates typically the target and measurement position of height measurement. is there.

  As shown in (1) of FIG. 2, the laser height sensor 6 includes a laser light irradiation unit 61 and a reflected light detection unit 62 that are arranged adjacent to each other. The laser beam irradiation unit 61 irradiates the laser beam L1 downward toward the substrate K that is an object disposed below. The laser beam L1 is reflected by the upper surface of the substrate K, and the reflected laser beam L2 enters the reflected light detector 62. The reflected light detection unit 62 detects the height H of the object from the difference in the detection position of the reflected laser light L2. In (1) of FIG. 2, the reflected laser light L2 when the substrate K is at the regular height H and the reflected laser light L3 when the substrate Kx is at the height H3 above the regular are illustrated. Yes.

  As shown in (2) of FIG. 2, the height measurement object of the laser height sensor 6 is the upper surface of the substrate K, and the height measurement is performed at a plurality of measurement positions. In the drawing, three measurement positions y1, y2, and y3 in the Y-axis direction of the substrate K are illustrated. Actually, height measurement is performed with a total of nine lattice points on the substrate K as measurement positions in consideration of three positions in the X-axis direction. In this case, if the substrate K is a flat plate and maintains a horizontal posture, the same height H is measured at all measurement positions. Further, as exemplified by broken lines in the figure, different heights h1 to h3 are measured at each measurement position on the warped substrate Kx. Also, when the substrate K is clamped at an inclination instead of a horizontal posture, different heights are measured at each measurement position. Note that a total of nine measurement positions are examples, and any desired number of arbitrary measurement positions can be set using the coordinate values of the planar coordinate system on the head drive mechanism.

  The component camera 5 is also used as an image camera for calibrating the measurement position of the laser height measuring device. The position of the component camera 5 is represented by a specific coordinate position in the plane coordinate system on the sensor moving mechanism, that is, the head drive mechanism, and the specific coordinate position corresponds to the calibration position. Further, the neutral density filter 7 is used as a jig for calibrating the measurement position of the laser height measuring apparatus.

  FIG. 3 is a diagram for explaining the calibration implementation status of the measurement position of the laser height measurement apparatus incorporated in the component mounter 1 of the embodiment, and a part of the cross section is shown. 4 is a partial perspective view in which the range from the laser height sensor 6 to the connecting portion 53 in FIG. 3 is enlarged. In FIG. 3, the laser height sensor 6 is positioned at a calibration position expressed in a plane coordinate system by a head driving mechanism. That is, the laser beam irradiation unit 61 of the laser height sensor 6 is positioned directly above the component camera 5. The component camera 5 has a light incident axis AO in the vertical direction and is mounted on the base 9 via a support base 52. The upper center of the component camera 5 is a light incident portion 51 where light from above enters. A cylindrical connecting portion 53 is disposed above the component camera 5, and a bowl-shaped upper end member 54 having no bottom and opened upward is disposed above the connecting portion 53. The component camera 5, the connecting portion 53, and the upper end member 54 share the light incident axis AO, and when the laser height sensor 6 is accurately positioned at the calibration position, the optical axis of the laser light L 1 is light. It overlaps the incident axis AO.

  An epi-illumination light source 531 made up of a number of LEDs is provided on one side surface of the inner wall of the connecting portion 53. Further, a half mirror 532 is provided obliquely across the inside of the connecting portion 53. The half mirror 532 reflects the incident light in the horizontal direction irradiated from the incident light source 531 vertically upward, and transmits the light from above toward the light incident portion 51 of the component camera 5. The open upper surface of the connecting portion 53 is covered with a transparent cover glass 533. A side light source 541 made up of a number of LEDs is provided on the bowl-shaped inner surface of the upper end member 54. The epi-illumination light source 531 and the side-illumination light source 541 are configured to illuminate the component from vertically below and obliquely from the side when the component camera 5 images the state of the component picked up by the suction nozzle 45. The incident light source 531 and the side light source 541 are turned off when the measurement position of the laser height measuring device is calibrated.

  The calibration jig 7 having the neutral density filter 71 is set on the upper surface of the upper end member 54 which is open like a bowl. FIG. 5 is a perspective sectional view showing the structure of the calibration jig 7 having the neutral density filter 71. The calibration jig 7 has a substantially axisymmetric shape centered on the light incident axis AO, and has an upper large-diameter base plate 72, a lower small-diameter press plate 73, a neutral density filter 71 therebetween, and a press screw 74. It consists of The base plate 72 and the presser plate 73 have a passage hole in the center, and a neutral density filter 71 is arranged and sandwiched between the two 72 and 73 so as to close the passage hole. The base plate 72 and the presser plate 73 are fixed by presser screws 74. The neutral density filter 71 is made of a resin film and transmits the laser light L1 emitted from the laser height sensor 6 while being attenuated at a predetermined attenuation rate. The attenuation factor of the laser beam of the neutral density filter 71 is appropriately selected so as to improve the accuracy of the position of the transmitted laser beam described later.

  The calibration jig 7 is not used during normal component mounting operation, and is set on an inner flange 542 provided inwardly on the upper surface of the upper end member 54 when calibrating the measurement position of the laser height measuring device. Used. At this time, as shown in FIG. 3, the neutral density filter 71 is disposed between the laser light irradiation unit 61 of the laser height sensor 6 and the light incident unit 51 of the component camera 5. Further, the height H of the neutral density filter 71 with respect to the laser height sensor 6 matches the normal height H (see FIG. 2) of the upper surface of the substrate K positioned at the component mounting position. In the embodiment, the calibration jig 7 is manually set and removed. However, the present invention is not limited to this, and the calibration jig 7 may be automatically set by adding a setting mechanism.

  In the situation shown in FIG. 3, calibration including laser light imaging means and correction value acquisition means is performed. In the laser beam imaging means, first, the laser height sensor 6 is positioned at the calibration position, that is, vertically above the light incident axis AO of the component camera 5 by the head driving mechanism. Next, the laser beam L1 is irradiated downward from the laser beam irradiation unit 61 toward the light incident unit 51 of the component camera 5. Then, the laser light L1 passes through the attenuation filter 71 while being attenuated to become transmitted laser light, and reaches the light incident portion 51 of the component camera 5. The component camera 5 captures the transmitted laser light and obtains a laser light image.

  The correction value acquisition means obtains a correction value based on the position of the transmitted laser beam on the laser beam image. For example, when there is almost no error in the position control of the calibration position by the head drive mechanism, the position of the transmitted laser beam is the center of the image area of the laser beam image. In this case, the correction value may be zero. However, when there is an error in the position control of the calibration position by the head drive mechanism, the position of the transmitted laser beam is shifted from the center of the image area of the laser beam image. In this case, a correction value corresponding to the deviation amount is set. The correction value is used to correct the coordinate position when the laser height sensor 6 is moved to the coordinate position on the substrate K.

  The calibration described above may be performed immediately after manufacturing the component mounting machine 1 and immediately after readjustment of the head drive mechanism or replacement of some components in a periodic inspection, etc. do not have to.

  Next, the operation of the laser height measuring apparatus in the component mounter 1 of the embodiment configured as described above will be described. FIG. 6 is an image example of a laser beam image obtained in the embodiment. (1) shows an entire region image, and (2) shows an enlarged image of the central portion of (1). In the entire region image of the laser light image of (1) in FIG. 6, the transmitted laser light is indicated by a small bright spot P1 substantially at the center. Further, in the center portion, the vertical 22 pixels × horizontal 28 pixels are enlarged (2), and the transmitted laser light is indicated by the bright spot P1 of several pixels. The position of the bright spot P1 coincides with the position of the light incident axis AO indicated by the intersection of the perpendicular thin lines. Therefore, in this case, the correction value is set to zero. If the position of the bright spot P1 of the transmitted laser beam is shifted from the position of the light incident axis AO, a correction value corresponding to the shift amount is set.

  On the other hand, FIG. 7 is an image example of a laser beam image obtained when the calibration jig 7 is not used. (1) is an entire region image, and (2) is an enlarged image of the central portion of (1). ing. When the calibration jig 7 is not used, the transmitted laser beam is indicated by an irregularly shaped bright area P2 in the entire region image of the laser beam image of (1) in FIG. In addition, in the enlarged central portion (2), the bright area P2 occupies most of the enlarged image. For this reason, it is difficult to accurately determine the position of the transmitted laser light, and an accurate correction value cannot be obtained.

  As is clear from a comparison between FIG. 6 and FIG. 7, the neutral density filter 71 has an effect of increasing the position of the transmitted laser light. In general, in the laser light irradiation unit 61 of the laser height sensor 6, the laser light L1 has some components around the optical axis due to internal irregular reflection and the like. The neutral density filter 71 has an effect of suppressing components around the laser beam L1 and extracting only the component at the center of the optical axis.

  FIG. 8 is another laser light image example for explaining the effect of the neutral density filter 71 to improve the position of the transmitted laser light. (1) is when the neutral density filter 71 is used, and (2) is the neutral density filter. 71 indicates when not in use. When the neutral density filter 71 shown in (1) of FIG. 8 is used, the transmitted laser light is indicated by a small shining area P3. Further, the shift amount with respect to the light incident axis AO of the area P3, that is, the correction value can be accurately obtained from the laser light image. On the other hand, when the neutral density filter 71 shown in (2) is not used, the transmitted laser light is indicated by a widely shining area P4. Further, a large number of bright spots are generated in a lattice shape. For this reason, even if the position of the transmitted laser beam can be estimated, it is difficult to accurately obtain the deviation amount with respect to the light incident axis AO, that is, the correction value.

  According to the component mounter 1 incorporating the laser height measuring apparatus of the embodiment, the position of the transmitted laser light on the laser light image is obtained with high accuracy by the action of the neutral density filter 71, and the light incident axis AO (calibration position) is obtained. ) As a correction value of the coordinate position. Further, when the laser height sensor 6 is moved to an arbitrary coordinate position on the substrate K by the head driving mechanism, the irradiation position of the laser beam, that is, the measurement position can be corrected using this correction value. That is, when the height measurement is performed at an arbitrary coordinate position on the substrate K, the laser height sensor 6 can be moved in consideration of the correction value by the head driving mechanism, and the measurement position can be accurately controlled.

  Further, even if there is a structural dimensional error due to a dimensional tolerance of components constituting the laser height sensor 6 or a variation in mounting work, the dimensional error is obtained as a correction value for each component mounting machine 1 and corrected. Can do. Therefore, the control accuracy of the measurement position can be maintained without requiring an attachment position adjustment mechanism or position adjustment work for the laser height sensor 6.

  Further, the correction value can be obtained using the calibration jig 7 having the neutral density filter 71 without changing the configuration of the conventional component mounting machine 1, and an arbitrary measurement position on the substrate K can be accurately controlled. . Accordingly, the height of the upper surface of the substrate K can be accurately measured at a plurality of positions, and a smooth component mounting operation can be performed even if the substrate K is warped.

  The laser height measuring apparatus of the present invention can be incorporated into a board production machine other than the component mounting machine 1 and equipment machines of other industries. In addition, the present invention can be variously applied and modified.

1: Component mounter 2: Board transfer device 21, 22: First and second guide rails 3: Component supply device 31: Cassette feeder 4: Component transfer device 41, 42: Y-axis rail moving table 43: Moving table
44: mounting head 45: suction nozzle 46: substrate camera 5: component camera (image camera) 51: light incident part 53: connection part 54: upper end member 6: laser height sensor 61: laser light irradiation part 62: reflected light detection Part 7: Calibration jig 71: Neutral filter 72: Base plate 73: Presser plate 74: Presser screw 9: Base L1: Laser beam L2, L3: Reflected laser beam AO: Light incident axis K, Kx, Ky: Substrate H, H3, h1 to h3: height

Claims (3)

A laser height sensor for measuring the height of the object having a laser light irradiation part for irradiating the object with laser light and a reflected light detection part for detecting the laser light reflected by the object; A laser height measuring device comprising a sensor moving mechanism for moving the laser height sensor in a plane,
An image camera arranged at a predetermined calibration position represented by a plane coordinate system on the sensor moving mechanism;
Laser light that is disposed between the laser light irradiation part of the laser height sensor positioned at the calibration position and the light incident part of the image camera, and is emitted from the laser light irradiation part toward the light incident part. A neutral density filter that attenuates and transmits light,
The laser height sensor is positioned at the calibration position, the laser beam is irradiated from the laser beam irradiation unit toward the light incident unit, and the laser beam transmitted through the neutral density filter is captured by the image camera. Laser beam imaging means for obtaining a laser beam image;
The coordinate position in the plane coordinate system of the laser beam irradiated from the laser beam irradiation unit toward the object when the laser height sensor is moved to the coordinate position of the plane coordinate system by the sensor moving mechanism Correction value acquisition means for obtaining the correction value based on the position of the laser beam on the laser beam image,
A laser height measuring device comprising: In claim 1,
The laser height measuring device is incorporated in a board production machine that produces a board on which components are mounted, and the object is a board clamped in a horizontal posture at a work position of the board production machine,
The said neutral density filter is a laser height measuring apparatus arrange | positioned by the horizontal attitude | position in the same height as the upper surface of the board | substrate clamped in the said working position. A board conveying device that carries a substrate into a component mounting position, positions and unloads it, a component supply device that supplies components, a mounting head that collects the components from the component supply device and mounts them on the positioned substrate, and the mounting A component transfer device having a head drive mechanism for driving the head in two orthogonal directions in a horizontal plane; and a component camera for imaging a component collected while the mounting head is moved from the component supply device onto the substrate; With
The laser height sensor of the laser height measuring device according to claim 1 or 2, is attached to the mounting head.
The head driving mechanism of the component transfer device is also used as the sensor moving mechanism of the laser height measuring device,
The component camera is also used as the image camera of the laser height measuring device,
The light reduction filter of the laser height measuring device is a component mounter that is disposed on the light incident portion of the component camera in a horizontal posture at the same height as the upper surface of the substrate positioned at the component mounting position.

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