JP2007183239A - Method and device for measuring board surface height - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve height measurement accuracy at an optional measuring object point on the mounting surface (board surface) of a circuit board, and to shorten a processing time. <P>SOLUTION: Height measuring points 12, 13 to the number of four or more in total are arranged on the board surface so as to be dispersed approximately equally on the whole board surface. After measuring all the height measuring points 12, 13, three adjacent height measuring points 12 or 13 are selected from among the height measuring points 12, 13, and processing for forming a triangular domain having the three height measuring points 12 or 13 as vertexes is repeated, to thereby divide the board surface into a plurality of triangular domains. Then, after selecting a triangular domain including the measuring object point whose height is to be actually measured from among the plurality of triangular domains, the height of the measuring object point within the triangular domain is calculated by interpolation calculation based on each height measured value of the three vertexes (height measuring points 12 or 13) of the triangular domain including the measuring object point. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a board surface height measuring method and apparatus for measuring the height of an arbitrary measurement target point on a circuit board mounting surface.

  When the electronic component mounting machine is used to apply solder to the circuit board mounting surface (hereinafter referred to as “board surface”) with a dispenser nozzle or to mount an electronic component adsorbed to the suction nozzle, the board surface is warped. Therefore, in order to increase the mounting accuracy, it is desirable to finely adjust the vertical stroke (lifting amount) of the dispenser nozzle and the suction nozzle with respect to the substrate surface according to the warp of the substrate surface. In order to realize this, it is necessary to measure the warpage (height) of the substrate surface, and several substrate surface height measurement techniques have been proposed for this purpose.

  For example, in the substrate surface height measurement technique described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-30793), the operator's input operation or the automatic indication of the positions of three recognition marks formed on the substrate surface Then, the heights of these three recognition marks are measured by a laser displacement sensor, and the heights of the three recognition marks are assumed on the assumption that the component mounting positions exist on the plane including these three recognition marks. The height of the component mounting position is calculated by linear interpolation based on the measured value.

  This Patent Document 1 does not specifically describe a method for selecting a recognition mark used for height measurement. In particular, when automating the selection of the recognition mark used for height measurement, if there is no appropriate selection criterion, the recognition mark at an inappropriate position will be selected, and the height of the component mounting position by linear interpolation will be selected. There is a disadvantage that the measurement accuracy is deteriorated.

  Further, the substrate warpage measurement technique described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2004-71641) divides the substrate surface into a plurality of quadrangular regions, and the height of the representative points of each quadrangular region is determined by a warp detector. The warpage of the entire substrate is estimated and calculated.

However, to increase the accuracy of warp detection using this method, the number of representative points (the number of square areas) needs to be considerably increased. For this reason, until all the representative points have been measured in height, There is a drawback that it takes time and the warp detection processing time becomes long.
Japanese Patent Laying-Open No. 2005-30793 (page 7, etc.) JP-A-2004-71641 (Page 7, etc.)

  As described above, the conventional substrate surface height (warp) measurement technique has the drawbacks that the height measurement accuracy deteriorates and the processing time becomes long.

  The present invention has been made in view of such circumstances, and therefore the object of the present invention is to improve the height measurement accuracy of any measurement target point on the substrate surface and reduce the processing time. It is to provide a measuring method and an apparatus thereof.

  In order to achieve the above object, the present invention provides a substrate surface height measuring method and apparatus for measuring the height of an arbitrary measurement target point on a circuit board mounting surface (hereinafter referred to as “substrate surface”). Select three adjacent height measurement points from four or more height measurement points set on the surface, and repeat the process of forming a triangular area with the three height measurement points as vertices The substrate surface is divided into a plurality of triangular areas, a triangular area including a measurement target point for actually measuring the height is selected from the plurality of triangular areas, and three vertices of the triangular area are selected. The height of the three height measurement points is measured by the height measurement means, and the height of the measurement target points in the triangular area is interpolated based on the height measurement values of the three height measurement points. It is made to calculate by.

  In this case, after dividing the substrate surface into a plurality of triangular areas, the heights of the three vertices (three height measuring points) of the triangular area including the measurement target point for which the height is actually measured are set. Although the measurement is performed, first, after measuring all four or more height measurement points set on the substrate surface, the substrate surface may be divided into a plurality of triangular regions.

  In either case, the substrate surface is divided into a plurality of triangular regions, a triangular region including the measurement target point for which the height is actually measured is selected, and three vertices (height measuring points) of the triangular region are selected. ) Is calculated by interpolation calculation based on the height measurement value of the triangle area, so that the measurement target is based on the height measurement values of three height measurement points close to the measurement target point. The height of the point can be calculated with high accuracy by interpolation calculation, and the processing time for height measurement can be shortened.

  In the present invention, when a substrate surface is divided into a plurality of triangular regions, when there are a plurality of candidates for a triangular region having a common side, the longer side of the other two sides is the shortest triangular region. The candidate may be selected as an effective triangle area.

  Alternatively, when the substrate surface is divided into a plurality of triangular regions, if there are a plurality of triangular region candidates that share one side, the candidate of the triangular region having the shortest total length of the other two sides is effective. You may make it select as a triangular area | region.

  In addition, when the substrate surface is divided into a plurality of triangular regions, if there are a plurality of candidates for a triangular region having one height measurement point as a common vertex, the total length of three sides or the longest side (3 A candidate for a triangular region having the shortest side) may be selected as an effective triangular region.

  Regardless of which method is used, the triangle area is adjusted so that the distance between the measurement target point where the height is actually measured and the apex (height measurement point) of the triangle area including the measurement target point is short. Therefore, the accuracy of the interpolation calculation can be improved.

  In addition, according to the present invention, when the substrate surface is not divided into a plurality of triangular areas, the measurement target point for which the height is actually measured among the four or more height measurement points set on the substrate surface is the most. Select three closest height measurement points, measure the height of the three height measurement points with the height measurement means, and measure the height based on the height measurement values of the three height measurement points. The height of the target point may be calculated by interpolation calculation. Even in this way, the height of the measurement target point can be calculated with high accuracy by interpolation calculation, and the processing time of the height measurement can be shortened.

  In the present invention, a dedicated height measuring device such as a laser displacement sensor may be used as the height measuring means for measuring the height of the height measuring point. The height of the height measurement point may be measured by combining a camera and slit light.

  In this case, it is provided with slit illumination means for irradiating the substrate surface with the slit light so as to straddle the height measurement point from obliquely above, and a camera for imaging the irradiated portion of the slit light from directly above the substrate surface. The height measurement point is calculated based on the position of the portion where the slit light imaged by the camera and the height measurement point overlap and the irradiation angle of the slit light. good. In this way, since the height of the height measurement point can be measured using a camera that is standard equipment on the electronic component mounting machine, a dedicated height measurement device such as a laser displacement sensor is not required, It can meet the demand for cost reduction.

  In the case of detecting the height of the height measurement point using a camera, a step of capturing an image of the irradiated portion of the slit light imaged by the camera only with the illumination of the slit illumination means [see FIG. 4 (a)] A step of capturing an image of the same part imaged by the camera in a state where all illumination including the slit illumination means is turned off [see FIG. 4 (b)], and from the illumination only image of the slit illumination means A step of extracting a difference image obtained by subtracting an image with all the lights off [see FIG. 4C], and a position of a portion where the slit light and the height measurement point overlap based on the difference image. The height of the height measurement point is calculated based on the detecting step and the position of the portion where the slit light and the height measurement point overlap and the irradiation angle of the slit light (see FIG. 4D). To carry out the process It may be. In this way, the height of the height measurement point is geometrically accurately calculated based on the position of the portion where the slit light imaged by the camera and the height measurement point overlap and the irradiation angle of the slit light. be able to.

  By the way, some circuit boards are opaque substrates that do not transmit visible light at all. However, semi-transparent or transparent substrates that transmit visible light (for example, translucent or transparent plastic substrates such as glass epoxy resin, glass substrates). Etc.). When such a semi-transparent or transparent substrate is irradiated with visible slit light from obliquely upward, as shown in FIG. 10 (a), not only the visible slit light is reflected on the upper surface of the substrate, Since the light passes through the inside of the substrate and is also reflected from the lower surface of the substrate, there are two types of reflected light 1 and 2 that are reflected at different positions when viewed from the camera side. For this reason, if the slit light of visible light is irradiated onto a translucent or transparent substrate, the position of the portion where the slit light of visible light and the height measurement point overlap cannot be accurately imaged by the camera, and the height measurement point It becomes impossible to calculate the height of.

  As a countermeasure, it is preferable to use an ultraviolet light camera having slit light formed by ultraviolet light and having sensitivity in the ultraviolet light region.

  Since ultraviolet light having a wavelength shorter than that of visible light has a property that it is difficult to transmit inside a translucent or transparent substrate, as shown in FIG. 10B, the slit light of the ultraviolet light is translucent or transparent. If it is irradiated obliquely from above, it is possible to almost prevent the transmission of the ultraviolet slit light into the translucent or transparent substrate, and the ultraviolet slit light can be reflected only on the upper surface of the substrate. It becomes possible. Therefore, even if it is a semi-transparent or transparent substrate, if the image is picked up by an ultraviolet camera having sensitivity in the ultraviolet region using the slit light of ultraviolet light, the position of the portion where the slit light and the height measurement point overlap Can be accurately captured by the camera, and the height of the height measurement point can be accurately calculated.

  Needless to say, visible light slit light may be used for an opaque substrate that does not transmit visible light at all.

  Hereinafter, two Examples 1 and 2, which embody the best mode for carrying out the present invention, will be described.

  A first embodiment of the present invention will be described with reference to FIGS. First, a system (height measuring means) for measuring the heights of predetermined height measuring points 12 and 13 set on the mounting surface of the circuit board 11 will be described with reference to FIGS.

  As shown in FIG. 1, on the mounting surface of the circuit board 11 (hereinafter simply referred to as “substrate surface”), recognition marks 12 for detecting the substrate position are formed with a conductor pattern or the like at two corner portions in the diagonal direction. Further, the plurality of height measurement points 13 are formed of a conductor pattern or the like so as to be distributed almost evenly over the entire substrate surface. Each height measurement point 13 may be formed as a conductor pattern dedicated to height measurement, or a part of the conductor wiring pattern formed on the substrate surface (a place suitable for height measurement) may be formed as the height measurement point 13. May be used as

  In the first embodiment, two recognition marks 12 for detecting the substrate position are also used as “height measurement points” (in the following description, the recognition marks 12 are also called “height measurement points”). A total of 4 or more height measurement points 12 and 13 (a total of 10 in the example of FIG. 1) are arranged on one substrate surface so as to be almost evenly distributed over the entire substrate surface.

  In the first embodiment, the height of the substrate surface height measurement points 12 and 13 is measured using a substrate position recognition camera 14 (see FIG. 2) that detects a recognition mark 12 for substrate position detection. A slit illumination device 16 (slit illumination means) that irradiates slit light 15 (see FIG. 4) at a predetermined inclination angle θ with respect to the optical axis of the substrate position recognition camera 14 has a predetermined positional relationship with the substrate position recognition camera 14. is set up. As shown in FIG. 3, the slit illumination device 16 is configured by arranging a light source 18 such as an LED, a slit glass plate 19, and a lens 20 in a case 17 in a line. The board position recognition camera 14 and the slit illumination device 16 are installed in a predetermined positional relationship with respect to the mounting head 21 (see FIG. 2) of the electronic component mounting machine. Note that a dispenser nozzle (not shown) for applying solder and a suction nozzle (not shown) for sucking electronic components are attached to the mounting head 21 downward.

  In this case, the height measurement points 12 and 13 are formed of a conductor pattern or the like so as to reflect the slit light 15 to the substrate position recognition camera 14 side, and the outer peripheral substrate surface is directed to the substrate position recognition camera 14 side. The reflection of the slit light 15 is reduced. For this reason, as shown in FIG. 4 (a), the illumination for photographing by the substrate position recognition camera 14 is turned off, and the slit light 15 of the slit illumination device 16 is tilted from the upper side to the height measurement point 12 or the substrate surface. 13, when the irradiated portion of the slit light 15 is photographed by the substrate position recognition camera 14, it overlaps with the height measurement point 12 or 13 in the slit light 15 irradiated on the substrate surface. Only the portion is captured as a bright image.

  Next, a method for measuring the heights of the height measurement points 12 and 13 using the substrate position recognition camera 14 and the slit illumination device 16 will be described with reference to FIG.

  First, the illumination of the substrate position recognition camera 14 is turned off, and the image of the height measurement point 12 or 13 is captured by the illumination of only the slit light 15 of the slit illumination device 16 [see FIG. 4 (a)]. Thereby, only the part which overlaps with the height measurement point 12 or 13 among the slit light 15 irradiated to the substrate surface is captured as a bright image. Thereafter, the slit light 15 of the slit illumination device 16 is also turned off, and an image of the same portion as described above is captured without any illumination [see FIG. 4B].

  Thereafter, a difference image (height measurement point 12 in the slit light 15) obtained by subtracting the image with no illumination shown in FIG. 4B from the image only of the slit light 15 shown in FIG. Or an image of a portion overlapping 13) (see FIG. 4C). Thereafter, the edge position of the portion where the slit light 15 and the height measurement point 12 or 13 overlap (for example, the edge position of the height measurement point 12 or 13 intersecting with the slit light 15) is detected using a pattern matching technique. . Then, the height of the height measurement point 12 or 13 is calculated based on the edge position of the slit light 15 in the difference image and the irradiation angle θ of the slit light 15.

For example, as shown in FIG. 5, when the point where the optical axis (center axis) of the slit light 15 intersects the optical axis (Z axis) of the substrate position recognition camera 14 is set to the reference height “0”, the slit light 15 The height z [μm] of the height measurement point 12 or 13 when the edge position is shifted by x [μm] in the X-axis direction is calculated by the following equation.
z = x / tan θ
Here, θ is an intersection angle between the optical axis of the slit light 15 and the optical axis of the substrate position recognition camera 14.

  By the way, some of the circuit boards 11 are opaque boards that do not transmit visible light at all. However, a semi-transparent or transparent board that transmits visible light (for example, a translucent or transparent plastic board such as glass epoxy resin, glass, etc. Substrate) and the like. When such a translucent or transparent substrate is irradiated with visible slit light 15 obliquely from above, the visible slit light 15 is simply reflected on the upper surface of the substrate as shown in FIG. However, since the light passes through the inside of the substrate and is reflected also on the lower surface of the substrate, there are two types of reflected light 1 and 2 that are reflected at different positions when viewed from the camera 14 side. For this reason, if the slit light 15 of visible light is irradiated to the translucent or transparent substrate 11, the position of the portion where the slit light of visible light and the height measurement point 12 or 13 overlap cannot be accurately imaged by the camera. The height of the height measurement point 12 or 13 cannot be calculated with high accuracy.

  As a countermeasure, the slit light 15 may be formed by ultraviolet light, and an ultraviolet light camera 14 having sensitivity in the ultraviolet light region may be used.

  Since ultraviolet light having a wavelength shorter than that of visible light has a property of being difficult to transmit into the semi-transparent or transparent substrate 11, the slit light of the ultraviolet light is semi-transparent or transparent as shown in FIG. By irradiating the substrate 11 obliquely from above, it is possible to almost prevent the transmission of the ultraviolet slit light into the translucent or transparent substrate 11, and the ultraviolet light slit light can be emitted only on the upper surface of the substrate 11. It becomes possible to reflect. Therefore, even if the substrate 11 is translucent or transparent, if the slit light 15 of ultraviolet light is used to capture an image with the ultraviolet light camera 14 having sensitivity in the ultraviolet light region, the slit light 15 and the height measurement point 12 or The position of the portion overlapping 13 can be accurately captured by the camera, and the height of the height measurement point 12 or 13 can be calculated with high accuracy.

  In the first embodiment, in addition to the slit illumination device 16 for ultraviolet light, a visible light illumination light source for illuminating the recognition mark 12 for substrate position detection with visible light is provided, and the spectral sensitivity characteristic is from the visible light region. Using a wide-range camera 14 up to the ultraviolet light region, first, the visible light source is turned on, and the recognition mark 12 for detecting the substrate position on the substrate 11 is imaged by the camera 14, and the visible light source is used. The light is turned off, the slit illumination device 16 for ultraviolet light is turned on, and the height of the height measurement point 12 or 13 is measured by the method described above.

  In the first embodiment, after all the height measurement points 12 and 13 set on the substrate surface are measured by the above-described method, three adjacent height measurement points 12 and 13 on the substrate surface are adjacent. The height measurement point 12 or 13 is selected, and the process of forming a triangular region having the three height measurement points 12 or 13 as vertices is repeated to divide the substrate surface into a plurality of triangular regions.

  In this triangular region forming step, first, from any one height measurement point 12 or 13, the other two height measurement points 12 or 13 are selected in a certain direction (for example, counterclockwise), A triangular area having three height measurement points 12 or 13 as vertices is formed.

  At this time, as shown in FIG. 6A, when there are a plurality of candidates for a triangular region having a common side, the candidate for the triangular region having the shortest long side among the other two sides is effective. Select as a triangle area.

  In this way, after forming the first one triangular area as shown in FIG. 6B, the same method is used to form one side of the formed triangular area as shown in FIG. 6C. A second triangular region to be shared is formed. Thereafter, the substrate surface is divided into a plurality of triangular regions by repeating the process of forming a new triangular region as shown in FIGS.

  After the substrate surface is divided into a plurality of triangular areas as described above, a triangular area including a measurement target point whose height is to be actually measured is selected from the plurality of triangular areas. At this time, as shown in FIG. 7, whether or not the measurement target point is included in the triangle area depending on whether or not the measurement target point exists on the triangle side of each straight line obtained by extending the three sides of the triangle area. What is necessary is just to determine.

  Then, based on the height measurement values of the three height measurement points 12 (or 13) which are the three vertices of the triangle region including the measurement target point, the height of the measurement target point in the triangle region is interpolated. Calculate by calculation. At this time, the interpolation calculation may use either linear interpolation or polynomial interpolation. When calculating the height of the measurement target point by linear interpolation, assuming that the triangular region is a plane and assuming that an arbitrary measurement target point is located on this plane, as shown in FIG. An intersection (point D) between a straight line connecting one vertex (point A) and a measurement target point (point E) in the triangular area and a straight line (base) connecting the other two vertices (point B and point C) Then, the height of the intersection (point D) is calculated by linear interpolation based on the height measurement values of the two vertices (point B and point C). Thereafter, the height of the measurement target point (point E) is calculated by linear interpolation based on the height measurement value of one vertex (point A) and the height of the intersection (point D).

  In addition, as shown in FIG. 1, since the region near the four sides of the substrate surface is located outside the triangular region, if there is a measurement target point in this region, the height of the measurement target point is set to Calculate or determine as follows.

  (1) When the measurement target points exist at the corner portions 22 at the four corners of the substrate surface, the height of the measurement target points coincides with the height measurement value of the measurement target point 12 or 13 located at the corner portion 22. It is considered to be.

  (2) When a measurement target point exists in a region near the four sides of the substrate surface other than the corner portion 22 (outside the triangular region), the height of the measurement target point is the height of the triangular region adjacent to the measurement target point. It is assumed that it matches the height of the corresponding point on the side. For example, when the XY coordinates of the measurement target point located outside the triangle area are (x1, y1), the height of the corresponding point on the side of the triangle area where the X coordinate is x1 or the Y coordinate is y1 is the triangle area. Are calculated by linear interpolation based on the height measurement values of the two vertices (height measurement point 12 or 13), and this is regarded as the height of the measurement target point.

  The height measurement of the height measurement points 12 and 13, the division of the triangular area, and the interpolation calculation of the height of the measurement target point described above are executed by a computer that processes the image of the substrate position recognition camera 14. Therefore, this image processing computer serves as height measuring means, triangular area dividing means, and interpolation calculating means in the claims.

  According to the first embodiment described above, the substrate surface is divided into a plurality of triangular regions, a triangular region including a measurement target point whose height is to be actually measured is selected, and the three triangular regions are selected. Since the height of the measurement target point in the triangle area is calculated by interpolation calculation based on the height measurement value of the vertex (height measurement point 12 or 13), the three heights close to the measurement target point are calculated. The height of the measurement target point can be accurately calculated by interpolation based on the height measurement value of the measurement point, and the processing time of the height measurement can be shortened.

  In the first embodiment, after all the height measurement points 12 or 13 set on the substrate surface are first measured, the substrate surface is divided into a plurality of triangular regions. After dividing into triangular regions, the heights of the three vertices (three height measuring points 12 or 13) of the triangular region including the measurement target points for which the height is actually measured are measured, and the 3 Based on the height measurement values of the individual height measurement points 12 or 13, the heights of the measurement target points in the triangular area may be calculated by interpolation calculation.

  In the first embodiment, when the substrate surface is divided into a plurality of triangular regions, when there are a plurality of candidates for a triangular region having one side in common, the longer one of the other two sides is the most. Although the short triangle area candidate is selected as an effective triangle area, the following method is conceivable.

  (1) When dividing a substrate surface into a plurality of triangular areas, if there are a plurality of triangular area candidates that share one side, the candidate for the triangular area with the shortest total length of the other two sides is effective. Select as a triangle area.

  (2) When the substrate surface is divided into a plurality of triangular regions, if there are a plurality of candidate triangular regions having one height measurement point as a common vertex, the triangle having the shortest total length of the three sides Select region candidates as valid triangle regions.

  (3) When the substrate surface is divided into a plurality of triangular regions, the longest side (the longest of the three sides) is present when there are a plurality of triangular region candidates having a single height measurement point as a common vertex. The candidate of the triangular area with the shortest side) is selected as an effective triangular area.

  Regardless of which method is used, the triangle area is adjusted so that the distance between the measurement target point where the height is actually measured and the apex (height measurement point) of the triangle area including the measurement target point is short. Therefore, the accuracy of the interpolation calculation can be improved.

  In addition, when dividing the substrate surface into a plurality of triangular areas, as shown in FIG. 9, if one of the triangular area candidates is included in the other triangular area candidate, the smaller triangular area candidate is selected. You may make it do.

  In the first embodiment, since the height of the height measuring points 12 and 13 is measured using the board position recognition camera 14 provided as a standard in the electronic component mounting machine, a dedicated laser displacement sensor or the like is used. Although there is an advantage that a height measuring device is not required and the demand for cost reduction can be satisfied, the present invention uses the height measuring means such as a laser displacement sensor to increase the height of the height measuring points 12 and 13. Needless to say, it may be possible to measure the thickness.

  In the first embodiment, the substrate surface is divided into a plurality of triangular regions, but in the second embodiment of the present invention, the height of the measurement target point is calculated by interpolation calculation without dividing the substrate surface into a plurality of triangular regions. How to do it.

  Also in the second embodiment, as in the first embodiment, a total of four or more height measurement points 12 or 13 are arranged on one substrate surface so as to be distributed almost evenly over the entire substrate surface. Then, the three height measurement points 12 or 13 closest to the measurement target point for which the height is actually measured are selected from the height measurement points 12 or 13 set on the substrate surface, and the three The height of the height measurement point 12 or 13 is measured by the same method as in the first embodiment, and the height of the measurement target point is determined based on the height measurement values of the three height measurement points 12 or 13. Calculated by interpolation calculation.

  In this method, it is considered that the measurement target point is often included in a triangular region having the three height measurement points 12 or 13 closest to the measurement target point as apexes. Depending on the arrangement condition, the measurement target point may not be included in the triangular region having the three height measurement points 12 or 13 closest to the measurement target point as vertices. In this case, the height of the measurement target point may be interpolated by extrapolation, or one or two of the three height measurement points 12 or 13 closest to the measurement target point. The height measurement point 12 or 13 is replaced with another height measurement point 12 or 13 so that the measurement target point is included in a triangular region having the three height measurement points 12 or 13 as vertices. Then, the height of the measurement target point may be calculated by interpolation.

  Also in the second embodiment described above, the same effect as in the first embodiment can be obtained.

It is a figure for demonstrating arrangement | positioning of the height measurement point of a board | substrate surface and division | segmentation of a triangular area | region in Example 1 of this invention. It is a figure explaining the structure of the system which measures the height of the height measurement point of a board | substrate surface using a board | substrate position recognition camera. It is sectional drawing of a slit illuminating device. It is a figure explaining the method of taking in the image of a height measurement point with the illumination of only the slit light of a slit illumination device, and detecting the edge position (edge position of a height measurement point) of slit light. It is a figure explaining the method of calculating the height of a height measurement point from the edge position (edge position of a height measurement point) of slit light. It is a figure explaining the procedure which divides | segments a board | substrate surface into several triangular area | regions. It is a figure explaining the method of selecting the triangular area | region in which the measuring object point which is going to actually measure height is included from several triangular area | regions. It is a figure explaining the method of calculating the height of the measurement object point in the said triangle area | region based on the height measurement value of the three vertex (height measurement point) of the triangle area | region containing a measurement object point by interpolation calculation. is there. It is a figure explaining the other method of dividing | segmenting a board | substrate surface into a some triangular area | region. (A) is a figure explaining the reflective state of light when the slit light of visible light is irradiated from diagonally upward with respect to a translucent or transparent board | substrate, (b) is with respect to a translucent or transparent board | substrate. It is a figure explaining the reflective state of light when the slit light of ultraviolet light is irradiated from diagonally upward.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Circuit board, 12 ... Recognition mark (height measurement point) for board position detection, 13 ... Height measurement point, 14 ... Board position recognition camera (height measurement means), 15 ... Slit light, 16 ... Slit illumination Device (slit illumination means), 21... Mounting head

Claims (17)

In a board surface height measuring method for measuring the height of an arbitrary measurement target point on a circuit board mounting surface (hereinafter simply referred to as “board surface”),
A process of selecting three adjacent height measurement points from among four or more height measurement points set on the substrate surface and forming a triangular region having the three height measurement points as vertices. A triangular region dividing step of repeatedly dividing the substrate surface into a plurality of triangular regions;
A triangle area including a measurement target point for actually measuring the height is selected from the plurality of triangle areas, and the heights of the three height measurement points serving as the three vertices of the triangle area are selected. And measuring the height of the measurement target point in the triangular region based on the height measurement value of the three height measurement points by interpolation calculation based on the height measurement means. Substrate surface height measurement method. In a board surface height measuring method for measuring the height of an arbitrary measurement target point on a circuit board mounting surface (hereinafter simply referred to as “board surface”),
A height measuring step of measuring four or more height measuring points set on the substrate surface by a height measuring means;
Three adjacent height measurement points are selected from the four or more height measurement points, and a process of forming a triangular region having the three height measurement points as vertices is repeated to form the substrate surface. A triangular region dividing step of dividing into a plurality of triangular regions;
A triangle area including a measurement target point whose height is to be actually measured is selected from the plurality of triangle areas, and the height measurement of three height measurement points which are the three vertices of the triangle area is selected. And calculating the height of the measurement target point in the triangular region based on the value by interpolation calculation.   In the triangular region dividing step, when there are a plurality of candidates for a triangular region having a common side, selecting a candidate for a triangular region having the shortest long side among the other two sides as an effective triangular region. The substrate surface height measuring method according to claim 1, wherein the substrate surface height is measured.   In the triangular region dividing step, when there are a plurality of candidates for a triangular region sharing one side, a candidate for a triangular region having the shortest total length of the other two sides is selected as an effective triangular region. The substrate surface height measuring method according to claim 1 or 2.   In the triangle area dividing step, when there are a plurality of triangle area candidates having one height measurement point as a common vertex, the triangle area candidate whose total length of the three sides or the shortest side is the shortest is the effective triangle The substrate surface height measuring method according to claim 1, wherein the region is selected as a region. In a board surface height measuring method for measuring the height of an arbitrary measurement target point on a circuit board mounting surface (hereinafter simply referred to as “board surface”),
From the four or more height measurement points set on the substrate surface, three height measurement points closest to the measurement target point to be actually measured are selected, and the three heights are selected. A substrate surface characterized in that the height of the measurement point is measured by a height measurement means, and the height of the measurement target point is calculated by interpolation calculation based on the height measurement values of the three height measurement points. Height measurement method. Using slit illumination means for irradiating the substrate surface with slit light so as to straddle the height measurement point from diagonally above, and using a camera for imaging the irradiated portion of the slit light from directly above the substrate surface And
The height measuring means calculates the height of the height measurement point based on the position of the portion where the slit light imaged by the camera and the height measurement point overlap and the irradiation angle of the slit light. The substrate surface height measuring method according to any one of claims 1 to 6. The slit illumination means forms the slit light with ultraviolet light,
The substrate surface height measuring method according to claim 7, wherein the camera is an ultraviolet light camera having sensitivity in an ultraviolet light region. In a board surface height measuring device that measures the height of an arbitrary measurement target point on a circuit board mounting surface (hereinafter simply referred to as “board surface”),
A height measuring means for measuring the height of four or more height measuring points set on the substrate surface;
Three adjacent height measurement points are selected from the four or more height measurement points, and a process of forming a triangular region having the three height measurement points as vertices is repeated to form the substrate surface. A triangular area dividing means for dividing into a plurality of triangular areas;
A triangle area including a measurement target point whose height is to be actually measured is selected from the plurality of triangle areas, and the height measurement of three height measurement points which are the three vertices of the triangle area is selected. Interpolation calculation means for calculating the height of the measurement target point in the triangular region based on the value by interpolation calculation.   The triangle area dividing means selects a triangle area candidate having the shortest long side of the other two sides as an effective triangle area when there are a plurality of triangle area candidates having a common side. The board | substrate surface height measuring apparatus of Claim 9 characterized by the above-mentioned.   The triangle area dividing means selects a triangle area candidate having the shortest total length of the other two sides as an effective triangle area when a plurality of triangle area candidates having one side in common exist. The board | substrate surface height measuring apparatus of Claim 9 characterized by the above-mentioned.   The triangle area dividing means is configured such that when there are a plurality of triangle area candidates having one height measurement point as a common vertex, the triangle area candidate having the shortest total length of three sides or the shortest longest side is an effective triangle. The substrate surface height measuring device according to claim 9, wherein the substrate surface height measuring device is selected as a region. In a board surface height measuring device that measures the height of an arbitrary measurement target point on a circuit board mounting surface (hereinafter simply referred to as “board surface”),
A height measuring means for measuring the height of four or more height measuring points set on the substrate surface;
From the four or more height measurement points, select the three height measurement points closest to the measurement target point to actually measure the height, and measure the height of the three height measurement points. Interpolation calculation means for calculating the height of the measurement target point based on the value by interpolation calculation.
Fixed device. Slit illuminating means for irradiating the substrate surface with slit light so as to straddle the height measurement point from diagonally above, and a camera for imaging the irradiated portion of the slit light from directly above the substrate surface ,
The height measuring means calculates the height of the height measurement point based on the position of the portion where the slit light imaged by the camera and the height measurement point overlap and the irradiation angle of the slit light. The board | substrate surface height measuring apparatus in any one of Claim 9 thru | or 13 characterized by these. The slit illumination means forms the slit light with ultraviolet light,
The substrate surface height measuring device according to claim 14, wherein the camera is an ultraviolet light camera having sensitivity in an ultraviolet light region. In the board surface height measurement method for measuring the height of the height measurement point provided on the mounting surface of the circuit board (hereinafter simply referred to as “board surface”),
Slit illuminating means for irradiating the substrate surface with slit light so as to straddle the height measurement point from diagonally above, and a camera for imaging the irradiated portion of the slit light from directly above the substrate surface Using an image capture system
Capturing an image of the irradiated portion of the slit light imaged by the camera only with the illumination of the slit illumination means;
Capturing the image of the same part as the above imaged by the camera with all the illumination including the slit illumination means turned off;
A step of extracting a difference image obtained by subtracting an image in a state in which all the illumination is turned off from an image of only illumination of the slit illumination means;
Detecting the position of the portion where the slit light and the height measurement point overlap based on the difference image;
Calculating the height of the height measurement point based on the position of the portion where the slit light and the height measurement point overlap and the irradiation angle of the slit light. Measuring method. The slit illumination means forms the slit light with ultraviolet light,
The substrate surface height measuring method according to claim 16, wherein the camera is an ultraviolet light camera having sensitivity in an ultraviolet light region.

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