JP6124900B2 - Substrate height correction method for substrate work equipment - Google Patents

Description

  The present invention relates to a method for correcting the height of a substrate that may cause deformation such as warpage or undulation when the substrate is worked using a substrate working device.

  There are solder printing machines, component mounting machines, reflow machines, board inspection machines, etc., as board working machines that perform predetermined operations on boards, and these are often connected by a board transfer device to build a board production line. . Among these, the component mounting machine includes a substrate holding device that holds the substrate in a horizontal posture at the reference height of the component mounting position, and a component transfer device that mounts the component collected from the component supply device on the held substrate. . The component transfer apparatus approaches the substrate from above, and performs the component mounting operation assuming that the substrate exists at the reference height. Here, if the board is deformed, such as warping or waviness, an error will occur in the work height, so impact stress will be applied to the part or the part mounting work will become unstable, resulting in the quality of the board to be produced. May decrease. In order to eliminate this fear, a technique for measuring the height of a plurality of points of the substrate held by the substrate holding device to grasp the deformation state and correcting the working height has been developed. 4.

  The component mounting apparatus disclosed in Patent Document 1 includes a measurement unit that measures a deviation of a substrate surface from a component placement reference surface, and an arithmetic process that calculates a correction amount of a mounting height by approximating warpage of the substrate surface using the deviation. And a mounting portion for mounting a component based on the correction amount. Further, in claim 3, it is disclosed that a quadratic function is used as a curved surface equation approximating the warpage of the substrate surface. And, by correcting the mounting height, the component is pressed and mounted on the board with appropriate pressure without excess and deficiency, so that component loss and mounting failure can be prevented and reliability of mounting work can be improved. Has been.

  In addition to the laser displacement sensor and the displacement measuring means for detecting the height of the printed circuit board or the inspection object on the printed board, the board inspection apparatus of Patent Document 2 includes means for specifying a plurality of measurement positions that do not transmit the laser, Means for calculating the height of the component mounting position based on the height detected at the position. Thereby, it is said that an accurate board height can be obtained regardless of the presence / absence of pattern lands around the component and the presence / absence of solder on the pattern lands.

  The electronic component mounting apparatus disclosed in Patent Document 3 includes a substrate measuring unit that detects the warpage and unevenness of the substrate by measuring the surface height of the substrate with a laser sensor, and a mounting electron that detects the height of the mounted electronic component. A part measuring means is provided, and in the embodiment, a grid-like measurement point is illustrated. Then, by checking the relationship between the surface height of the substrate, the height of the electronic component, and the thickness of the electronic component on the first substrate, the mounting height of the electronic component can be accurately corrected on the second and subsequent substrates. It is described that production efficiency is improved.

  A working device for a circuit board disclosed in Patent Document 4 is a measuring unit that measures a measurement displacement amount from a work reference plane at three or more measurement points on a work surface of a circuit board and a plurality of auxiliary measurement points in the vicinity of each measurement point. And calculating means for assuming a work surface by a curved surface model based on the measured displacement amount at the measurement location when the measured displacement amount is within the threshold value range. Further, claim 8 discloses an aspect in which assumption is made by a curved surface model for each partitioned work surface obtained by partitioning the work surface of the circuit board into a plurality of regions. The embodiment discloses a mode in which the equation of the curved surface model is expressed by a quadratic function. Accordingly, it is described that even if there is a discontinuous surface due to a step, a slit, a notch or the like on the circuit board, the work quality is not deteriorated.

JP 2000-299597 A JP 2005-30793 A JP 2010-186940 A International Publication 2007/063763

  By the way, as disclosed in Patent Documents 1 to 4, in the technique of correcting the work height by measuring the height of the substrate and approximating the deformation of the substrate by a quadratic function or the like, if the number of measurement points is increased, The height correction accuracy is improved by that amount. For example, when considering the cross-sectional shape in a specific direction of the substrate, the deformation of the upper warp in which the center of the substrate protrudes upward and vice versa is approximated from the height of three measurement points aligned in the specific direction. If four or more measurement points are set, the height correction accuracy is improved. Further, for the undulation-like deformation in which the unevenness is joined, the height can be set at four or more measurement points and approximated using, for example, a cubic function. However, when the number of measurement points is increased, a lot of time is required for the movement and measurement operation of the height measuring apparatus, and the throughput of the substrate production is accordingly reduced.

  On the other hand, this type of substrate is mass-produced on a lot basis, and a large number of substrates in the same lot generally exhibit a similar deformation state. Therefore, if a sample substrate is selected from the same lot and the tendency of the deformation state is confirmed in advance, the number and position of the measurement points can be optimized, and height correction accuracy can be secured even if the number of measurement points is narrowed down. It is done. This is expected to improve throughput during mass production of substrates.

  Further, in order to measure the height of the substrate in a non-contact manner, the laser displacement sensors exemplified in Patent Documents 2 and 3 are frequently used, but there are restrictions on the position setting of the measurement points. That is, the measurement point cannot be set on the substrate material surface through which most of the laser light is transmitted, and is usually set only on a circuit pattern that reflects the laser light well. Furthermore, in recent years, circuit patterns have been thinned in order to achieve high-density mounting of components, and the positions of measurement points having a sufficient width for height measurement are limited. For this reason, there are often cases where it is not possible to set regular measurement points, for example, grid-like measurement points exemplified in Patent Document 3. Then, when obtaining an approximate function representing the deformation of the substrate, the calculation processing becomes complicated and complicated, and the calculation accuracy tends to be lowered.

  Furthermore, the techniques for approximating the deformation of the substrate exemplified in Patent Documents 1 and 4 with a quadratic function are not necessarily highly accurate. For example, since it is considered that the substrate is deformed into a generally spherical shape by the above-described warping or downward warping deformation, it is preferable to approximate the cross-sectional shape in a specific direction with an arc rather than a quadratic function. In addition, it is not possible to approximate the wavy deformation where the concavities and convexities are joined by a quadratic function or an arc, and it is necessary to use a more complicated function or to divide the substrate into a plurality of regions and approximate the deformation in each region. There is.

  Note that the problems of height correction accuracy and throughput contradicting each other depending on the increase / decrease in the number of height measurement points described above, the problem of position setting of measurement points, and the problem of accuracy of functions approximating deformation are It is not limited to the component mounting work of the mounting machine. For example, when an adhesive is applied to temporarily attach a component with a component mounter, an error in work height causes a shift in the coating range and uneven coating. Further, for example, even in a drawing type solder printer having a dispenser device or an ink jet device, an error in the working height causes a shift in a drawing range and a solder thickness unevenness.

  The present invention has been made in view of the above-described problems of the background art, and the work for a substrate with improved height correction accuracy while limiting the number of measurement points of the substrate height to suppress the decrease in the throughput of substrate production. It is an object to be solved to provide a substrate height correction method for an apparatus.

An invention of a substrate height correcting method for a substrate working device according to claim 1 that solves the above-described problem is that a substrate is held in a horizontal posture by a substrate holding device of the substrate working device, and a substrate on the substrate by a height measuring device. Based on a measurement point height measurement step for measuring the measurement values of the heights of a plurality of measurement points and three or more measurement points arranged in a straight line, the cross-sectional shape in the straight line direction of the substrate is approximated by a smooth curve. and, the three or more sets of theoretical points between the measurement point, and the theoretical point height calculation step of calculating using said smooth curve the height of the theoretical value of the theoretical point, along the same line parallel to Based on a combination of three or more measurement points and theoretical points or three or more theoretical points arranged in a straight line, the straight line cross-sectional shape of the substrate is approximated by a smooth curve, and the measurement points and the theoretical points are approximated. New logic between theoretical points or between the theoretical points Set the point, calculate the theoretical value of the height of the new theoretical point using the smooth curve, and set the new theoretical point and the theoretical value until the desired number of theoretical points and theoretical values are obtained The theoretical point setting repetition step for repeating the calculation of the above, and the working point height correction for calculating the correction value of the desired working point height on the substrate using the measured value of the measuring point and the theoretical value of the theoretical point Steps.

According to a second aspect of the present invention, there is provided a measurement point height in which the substrate is held in a horizontal posture by the substrate holding device of the substrate working device, and the height measurement values of the plurality of measurement points on the substrate are measured by the height measurement device. Based on the measurement step and three or more measurement points arranged in a straight line, the cross-sectional shape in the straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating the theoretical value of the theoretical point height using the smooth curve, and using the measured value of the measuring point and the theoretical value of the theoretical point on the substrate, A working point height correction step for calculating a correction value for the desired working point height, and the theoretical point height when there is no third measuring point arranged when focusing on a specific straight line. Prior to the calculation step, a substitute point to replace the third measurement point is determined as the special point. Is set on a straight line, and three auxiliary measurement points are set around the substitute point, and a larger weight is assigned as the distance from the substitute point is smaller. The substitute point height is obtained by measuring the auxiliary measurement value of the height of the measurement point, multiplying each auxiliary measurement value by the weight value, and adding the weighted average value to the substitute measurement value of the substitute point height. The theoretical point height calculating step treats the substitute point and the substitute measurement value as the third measurement point and measurement value.

According to a third aspect of the present invention, there is provided a measurement point height in which the substrate is held in a horizontal posture by the substrate holding device of the substrate working device, and the height measurement values of the plurality of measurement points on the substrate are measured by the height measurement device. Based on the measurement step and three or more measurement points arranged in a straight line, the cross-sectional shape in the straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating the theoretical value of the theoretical point height using the smooth curve, and using the measured value of the measuring point and the theoretical value of the theoretical point on the substrate, A work point height correction step for calculating a correction value for a desired work point height of the desired point, and when the theoretical point height calculation step focuses on a specific straight line, the three or more measurement points Cross-section between two specific measurement points with multiple combinations Can be approximated by a plurality of smooth curves, and when the plurality of smooth curves do not coincide with each other, an average curve passing between the plurality of smooth curves is obtained, and the specific 2 The theoretical value of the height of the theoretical point between two measurement points is calculated using the average curve.

According to a fourth aspect of the present invention, there is provided a measuring point height in which the substrate is held in a horizontal posture by the substrate holding device of the substrate working device and the height measurement values of the plurality of measuring points on the substrate are measured by the height measuring device. Based on the measurement step and three or more measurement points arranged in a straight line, the cross-sectional shape in the straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating the theoretical value of the theoretical point height using the smooth curve, and using the measured value of the measuring point and the theoretical value of the theoretical point on the substrate, A working point height correction step for calculating a correction value for a desired working point height, and in the measuring point height measurement step, the substrate holding device sets a specific position of the substrate to a reference height. holding, a neighbor point closer to the specific part portion of the measuring points Set, measurement of the height of the near point and the reference height without measurement by the height measuring device.
According to a fifth aspect of the present invention, in the second aspect, in the measurement point height measurement step, the substrate holding device holds a specific location of the substrate at a reference height, and a nearby point close to the specific location is the auxiliary. It is set as a part of the measurement point, and the auxiliary measurement value of the height of the neighboring point is set as the reference height without performing the measurement by the height measuring device.

According to a sixth aspect of the present invention, there is provided a measurement point height in which the substrate is held in a horizontal posture by the substrate holding device of the substrate working device, and the height measurement values of the plurality of measurement points on the substrate are measured by the height measurement device. Based on the measurement step and three or more measurement points arranged in a straight line, the cross-sectional shape in the straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating the theoretical value of the theoretical point height using the smooth curve, and using the measured value of the measuring point and the theoretical value of the theoretical point on the substrate, They desired a working point height correction step of calculating a correction value of the height of the working point which has a pre-Symbol predetermined to keep measuring a plurality of measurement points on the substrate at the measurement point height measurement step of A point determination step, wherein the measurement point determination step comprises: Elected sample substrate from a number of the substrate in the same lot, a sample measuring step of measuring the sample measurements is the height of the large number of samples measurement point on the sample substrate, a reference point the number of sample measurement points And a comparison point calculation step for calculating an estimated value of the height of the comparison point using the sample measurement value of the reference point, and a correlation between the sample measurement value and the estimation value at the comparison point When the correlation is determined to be insufficient, the reference point is changed or increased to return to the comparison point calculation step, and when the correlation is determined to be excessive, the reference point And a return to the comparison point calculation step, and a validity determination step of determining the reference point as the measurement point when it is determined that the correlation is appropriate.

The invention according to claim 7 is the invention according to claim 6 , wherein, in the validity determination step, a difference value is obtained by subtracting the estimated value from the sample measurement value of each comparison point, and any one of the difference values is a predetermined value. It is determined that the correlation is insufficient when an allowable value is exceeded, and it is determined that the correlation is excessive when all difference values are significantly lower than the allowable value, and all the difference values are determined. Is less than the tolerance and it is difficult to reduce the reference point, it is determined that the correlation is appropriate.

The invention according to claim 8 is the invention according to claim 6 or 7 , wherein in the comparison point calculation step, the reference point and the sample measurement value thereof are regarded as the measurement point and the measurement value, and the comparison point and the estimated value are is regarded as working points and the correction value, it performs the theoretical point height calculation step and the working point height correction step.

The invention according to claim 9 is obtained by subtracting the estimated value from the sample measured value, the estimated value, and the sample measured value in the validity determination step according to any one of claims 6 to 8. One or more data groups consisting of at least one difference value are displayed in different colors or symbols according to the magnitude of the values.
The invention according to claim 10 is the work point height correction step according to any one of claims 1 to 9, wherein the substrate is formed by a combination of a large number of triangular regions having the measurement point and the theoretical point as vertices. Dividing and approximating that the substrate is a plane in each of the triangular regions, the height correction value of the working point is calculated using the triangular region including the working point.
The invention according to an eleventh aspect is the one according to any one of the first to tenth aspects, wherein in the theoretical point height calculation step, the cross-sectional shape is approximated by an arc based on three measurement points arranged in a straight line. .

  In the invention of the substrate height correction method for a substrate working device according to claim 1, the cross-sectional shape of the substrate is approximated by a smooth curve based on three or more measurement points arranged in a straight line, and between the measurement points. A theoretical point is set and a theoretical value of the height is calculated, and a desired correction value of the height of the working point is calculated using the measured value of the measuring point and the theoretical value of the theoretical point. Therefore, compared with the prior art that calculates the correction value of the work point using only the measurement value of the measurement point, the height correction accuracy can be improved because the height correction can be performed based on a larger number of measurement points and theoretical points. . In addition, the actual measurement of moving the height measurement device is limited to only the measurement point, and the theoretical value of the theoretical point height is calculated by an arithmetic process that can be performed in a shorter time than the actual measurement. The time required does not increase significantly from the prior art. Accordingly, it is possible to suppress a decrease in the throughput of substrate production.

Furthermore, since the desired number of theoretical points and theoretical values are obtained in the theoretical point setting repetition step, the height correction accuracy can be significantly improved. In addition, the setting of a new theoretical point and the calculation of the theoretical value of the height are all performed by arithmetic processing, and it is not necessary to add actual measurement using a height measuring device, so the time required for height correction is greatly increased. The increase in the substrate production throughput can be suppressed.

In the invention according to claim 2 , when there is no third measurement point arranged when focusing on a specific straight line, the substitute point is set on the specific straight line, and the height of the surrounding three auxiliary measurement points is set. The weighted average value is used as a substitute measurement value and is replaced with the third measurement point. Therefore, even when the third measurement point cannot be set on a straight line due to restrictions on the structure of the substrate, for example, restrictions on the arrangement of circuit patterns capable of measuring the height, the height correction accuracy can be improved.

In the invention according to claim 3 , when a plurality of smooth curves approximating the cross-sectional shape between two specific measurement points do not coincide with each other, the height of the theoretical point between the two specific measurement points is high. The theoretical value is calculated using an average curve. Thereby, four or more measurement points are set on a specific straight line, and it is possible to accurately approximate a complicated deformation, such as a wavy deformation in which concave and convex portions are joined, rather than simple upward warping or downward warping. Furthermore, it is possible to accurately approximate a region where the aspect of deformation changes, for example, a boundary region in the middle of changing from a convex deformation region to a concave deformation region.

In the inventions according to claims 4 and 5 , a point near the specific location of the substrate held at the reference height by the substrate holding device is set as a measurement point or a part of the auxiliary measurement point, and actual measurement is omitted. Use the reference height. Therefore, it is possible to reduce the number of measurement points or auxiliary measurement points at which measurement is performed using the height measuring apparatus, further suppressing an increase in the time required for height correction, and further suppressing a decrease in substrate production throughput.

The invention according to claim 6 further includes a measurement point determination step for determining a plurality of measurement points on the substrate in advance, and the measurement point determination step includes a sample measurement step, a comparison point calculation step, and a validity determination step. Is included. Then, in the sample measurement step, the heights of a large number of sample measurement points are measured to confirm the deformation state of the sample substrate in advance with accuracy, and from the temporarily determined reference points in the comparison point calculation step and the validity determination step. A measurement point is determined by judging whether or not the deformation of the sample substrate can be approximated with sufficient accuracy. Therefore, it is possible to optimize the measurement position while limiting the number of height measurement points for a large number of substrates exhibiting similar deformation states in the same lot, and to approximate the deformation of the substrate with sufficient accuracy. Thereby, the number of height measurement points at the time of substrate mass production can be limited, and the throughput of substrate production is improved.

In the invention according to claim 7 , it is objectively determined whether or not the approximate correlation of the deformation of the sample substrate is appropriate based on the magnitude of the difference value obtained by subtracting the estimated value from the sample measurement value at the comparison point. Therefore, the number of height measurement points and the measurement position during mass production can be reliably optimized. In addition, since it is possible to automatically determine the appropriateness of the approximate correlation, the labor of the operator is reduced.

In the invention which concerns on Claim 8 , the theoretical point height calculation step and work point height correction step as described in any one of Claims 1-7 are performed at a comparison point calculation step. That is, when the deformation of the sample substrate is approximated based on the sample measurement values of the limited reference points, the estimated value of the comparison point is calculated by the same arithmetic processing method as that at the time of substrate mass production. As a result, the deformation approximation method is consistent between the sample substrate for determining the validity of measurement points and many substrates during mass production, and even if the number of height measurement points during mass production is limited, the substrate can be reliably deformed. Can be approximated with sufficient accuracy.

In the invention according to claim 9 , in the validity determination step, one or more of the data groups including the sample measurement value, the estimated value, and the difference value are displayed by color coding or symbol coding according to the magnitude of the value. Thereby, even when the operator determines the approximate correlation, the determination can be easily made visually, and the troublesome and delicate determination is reduced.
In the invention according to claim 10, the substrate is divided by a combination of a large number of triangular regions having the measurement points and the theoretical points as vertices, and the triangular region including the work points is approximated by a plane to correct the height of the work points. Is calculated. In other words, the deformation of the entire substrate is approximated by a smooth cross-sectional curve, and the height of the desired work point is corrected by locally regarding the substrate as a plane. Thereby, the height correction accuracy can be improved without complicating the arithmetic processing unnecessarily. In addition, an increase in the time required for height correction can be suppressed, and a decrease in throughput of substrate production can be suppressed.
In the invention according to the eleventh aspect, since the cross-sectional shape of the substrate is approximated by an arc based on the three measurement points arranged in a straight line, the deformation of the upper and lower warpage of the spherical surface having a relatively high occurrence frequency is obtained. Thus, the height correction accuracy is better than the conventional technique of approximating with a quadratic function.

It is a perspective view explaining the structure of the component mounting machine which performs the board | substrate height correction method of the working apparatus for boards of 1st-5th embodiment. (1) is a diagram schematically illustrating a configuration of a laser height sensor and a height detection method, and (2) is a diagram schematically illustrating a measurement example at a plurality of measurement points on a substrate. It is a figure of the flowchart explaining the board | substrate height correction method of the working apparatus for board | substrates of 1st Embodiment. It is a top view of the board | substrate explaining the specific example of arrangement | positioning of the measurement point in 1st Embodiment. It is a figure which illustrates the arithmetic processing performed at the theoretical point height calculation step of 1st Embodiment. It is a top view of the board | substrate explaining the specific example of arrangement | positioning of the measurement point and theoretical point at the time of the theoretical point height calculation step being complete | finished in 1st Embodiment. It is a top view of the board | substrate explaining the specific example of arrangement | positioning of the measurement point and theoretical point at the time of the theoretical point setting repetition step being complete | finished in 1st Embodiment. It is a figure explaining the arithmetic processing performed at the work point height correction step of 1st Embodiment by a specific example. It is a top view of the board | substrate which illustrates and explains the height correction method of a prior art. It is a figure of the flowchart explaining the board | substrate height correction method of the working apparatus for board | substrates of 2nd Embodiment. It is a figure which illustrates the calculation processing content performed at the substitute point height measurement step of 2nd Embodiment. It is a figure explaining the application form of the substitute point height measurement step of 2nd Embodiment. It is a top view of the board | substrate explaining the specific example of arrangement | positioning of the measurement point in 3rd Embodiment. It is a figure which illustrates the content of the arithmetic processing performed at the theoretical point height calculation step of 3rd Embodiment. It is a figure of the flowchart explaining the detail of the measurement point determination step in 4th Embodiment. In 4th Embodiment, it is a top view of the sample board | substrate which displayed the measurement result of the sample measurement step typically. In 4th Embodiment, it is a top view of the sample board | substrate which displayed typically the state which divided many sample measurement points into the reference point and the comparison point. In 4th Embodiment, it is a top view of the sample board | substrate which displayed the difference value in a comparison point graphically.

  First, a component mounter 1 that performs a board height correcting method for board working equipment according to first to fifth embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view illustrating a configuration of a component mounter 1 that performs a board height correcting method for a board working apparatus according to first to fifth embodiments. The component mounter 1 corresponds to a board working device, and is configured by assembling a substrate transport device 2, a component supply device 3, a component transfer device 4, and a component camera 5 on a machine base 9. The mounting head 44 of the component transfer device 4 is provided with a laser height sensor 6 corresponding to the height measuring device used in the present invention. Each of the devices 2 to 6 is controlled by a control computer (not shown), and each performs a predetermined operation.

  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 extend in the transport direction (X-axis direction) across the upper center of the machine base 9 and are assembled to the machine base 9 so as 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 into and out of the component mounting position set at the center of the machine base 9.

  Further, a clamping device corresponding to the substrate holding device used in the present invention is provided at a position not visible in the figure below the conveyor belt at the center of the machine base 9. The clamp device pushes up the substrate K, clamps it in a horizontal posture, and positions it at the component mounting position. At this time, the two edges near the first and second guide rails 21 and 22 of the substrate K are specific places held at the reference height H0. When no deformation such as warpage or undulation occurs in the substrate K, the entire substrate K is held at the reference height H0. If the substrate K is deformed, the height of the substrate K depends on the position. The height changes from the reference height H0.

  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 moving table 43, a mounting head 44, a nozzle holder 45, a suction nozzle 47, a substrate 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 machine base 9 (the right back side in FIG. 1) to the upper part of the front part supply device 3. A movable table 43 is supported on the Y-axis rails 41 and 42 so as to be movable in the Y-axis direction. A mounting head 44 is provided on the moving table 43 so as to be movable in the X-axis direction. A nozzle holder 45 is provided on the front surface of the mounting head 44 so as to protrude downward. Further, the nozzle holder 45 is provided with a suction nozzle 47 for picking up and mounting components by using negative pressure. A substrate camera 46 that images the substrate K is provided on the bottom surface of the mounting head 44 so as to face downward.

  The mounting head 44 of the component transfer device 4 is driven in two horizontal directions (XY directions) by two servo motors. A head drive mechanism is constituted by the two servo motors, the Y-axis rails 41 and 42, the moving table 43, and the like. Further, the suction nozzle 47 is driven in the vertical direction by another servo motor. As a result, the suction nozzle 47 picks up and picks up the component from the cassette type feeder 31 of the component supply device 3, approaches the positioned substrate K from above, and mounts the component on the mounting point on the substrate K. The mounting point corresponds to the working point of the present invention for correcting the working height, and the position is represented and controlled by the coordinate value of the plane coordinate system on the head driving mechanism. The board camera 46 reads the fiducial mark of the board K that has been positioned, and detects a position error of the board K relative to the component mounting position. Thereby, the coordinate value on the board | substrate K is calibrated and position control is performed correctly.

  The component camera 5 is provided upward on the upper surface of the machine 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 47 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 component mounting machine 1 includes a control computer (not shown). The control computer is based on various information including the correspondence between the board type of the board to be produced and the component 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. The control computer controls execution of the substrate height correction method of the first to third embodiments.

  Next, the laser height sensor 6 will be described. As shown in FIG. 1, the laser height sensor 6 is attached to the bottom surface of the mounting head 44 in a downward direction along with the substrate camera 46. Therefore, the laser height sensor 6 is moved by the mounting head 44. 2A is a diagram schematically illustrating the configuration of the laser height sensor 6 and the height detection method, and FIG. 2B schematically illustrates an example of measurement at a plurality of measurement points on the substrate K. It is a figure to do.

  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 disposed below. The laser beam L 1 is reflected on the upper surface of the substrate K, and the reflected laser beam L 2 reflected obliquely enters the reflected light detector 62. The reflected light detection unit 62 detects the height H of the substrate K from the difference in the detection position of the reflected laser light L2. In (1) of FIG. 2, the reflected laser beam L2 when the substrate K is at the reference height H0 and the reflected laser beam L3 when the substrate Ka is at a height Ha higher than the reference height H0 are illustrated. Has been.

  Further, as illustrated in (2) of FIG. 2, the laser height sensor 6 performs height measurement at a plurality of measurement points on the substrate K. In the figure, three measurement points y1 to y3 in the Y-axis direction of the substrate K are illustrated. In this case, if the substrate K is not deformed, the same reference height H0 is measured at the three measurement points y1 to y3. Further, as exemplified by broken lines in the figure, different heights H1 to H3 are measured at the measurement points y1 to y3 on the substrate Kb deformed upward. The measurement points y1 to y3 are examples, and any desired number of measurement points can be set using coordinate values. However, in order to perform stable height measurement, it is preferable to set a measurement point on a circuit pattern that reflects the laser beam L1 well and at a position having a certain width or more.

  Next, the substrate height correction method of the first embodiment will be described with reference to FIGS. FIG. 3 is a flowchart illustrating the substrate height correction method for the substrate working apparatus according to the first embodiment. The substrate height correction method of the first embodiment includes a measurement point determination step S1, a measurement point height measurement step S2, a theoretical point height calculation step S3, a theoretical point setting repetition step S4, and a work point height correction step S5. Have.

  In the measurement point determination step S1, a plurality of measurement points on the substrate in the next measurement point height measurement step S2 are determined in advance. The measurement point determination step S1 can be performed based on empirical rules, although detailed steps described in the fourth and fifth embodiments below can be taken. That is, if conditions such as the size, shape, thickness, and material of the substrate K are taken into consideration, it is possible to roughly predict how and how much the substrate K is deformed. Therefore, the number and position of the measurement points are determined in advance so that the expected deformation can be sufficiently approximated.

  In the first embodiment, nine measurement points P1 to P9 shown in FIG. 4 are set on the substrate K1. FIG. 4 is a plan view of the substrate K1 for explaining a specific example of the arrangement of the measurement points P1 to P9 in the first embodiment. As shown in the drawing, nine measurement points P1 to P9 are set in a grid pattern on a rectangular substrate K1. The measurement point P5 is set at the center position of the substrate K1, and the other measurement points P1 to P4 and P6 to P9 are set to positions slightly inward from the edge of the substrate K1. Each of the measurement points P1 to P9 is set on the circuit pattern of the substrate K1, and a stable height measurement is performed by the laser height sensor 6.

  In the measurement point height measurement step S2, the substrate K1 is held in a horizontal posture by the clamp device, and the measurement values of the nine measurement points P1 to P9 on the substrate K1 are measured by the laser height sensor 6. The laser height sensor 6 is driven by two servo motors, and sequentially moves above the respective measurement points P1 to P9 to obtain a height measurement value. In addition, since there is no restriction | limiting in a measurement order, it is preferable to select the measurement order from which the total of the movement time of the laser height sensor 6 becomes the shortest.

  In the theoretical point height calculation step S3, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve based on three or more measurement points arranged on a straight line, and a theoretical point is obtained between the three or more measurement points. And the theoretical value of the theoretical point height is calculated using the smooth curve. In the specific example of FIG. 4, a total of three straight lines passing through three measurement points parallel to the long side of the substrate K1 and three straight lines passing through three measurement points parallel to the short side of the substrate K1. The calculation process is performed six times.

  FIG. 5 is a diagram illustrating the calculation process performed in the theoretical point height calculation step S3 of the first embodiment. In FIG. 5, large arrows indicate measurement points, and small arrows indicate theoretical points. FIG. 5 illustrates the case where attention is paid to a straight line L1 (shown in FIG. 4) parallel to the long side of the substrate K1 and passing through the three central measurement points P4, P5, and P6. In the theoretical point height calculation step S3, first, the cross-sectional shape of the substrate is approximated by an arc based on three measurement points arranged in a straight line. That is, the cross-sectional shape of the substrate K1 is approximated by the arc C1 from the measured values h4, h5, h6 of the heights of the measurement points P4, P5, P6. Here, if the measured values h4, h5, and h6 are represented with positive and negative signs with the reference height H0 as zero, the measured values h4, h5, and h6 are all positive values, and h4 <h6 <h5. It has become. Therefore, the substrate K1 is warped and the center of the arc C1 is obtained below the substrate K1.

  In addition, a warping deformation may occur in another substrate, and an approximate arc center may be obtained above the substrate. Furthermore, the radius of the approximate arc can be increased without limit, and the cross-sectional shape of the substrate can be approximated by a straight line.

  Next, a theoretical point is set between the measurement points. In the specific example, a theoretical point Q45 is set at an intermediate point between the measurement point P4 and the measurement point P5, and a theoretical point Q56 is set at an intermediate point between the measurement point P5 and the measurement point P6. Third, the theoretical value of the theoretical point height is calculated using a smooth curve. In the specific example, the theoretical values h45 and h56 of the respective heights are calculated on the assumption that the theoretical point Q45 and the theoretical point Q56 exist on the arc C1.

  Similarly, the same calculation process is performed for the other five straight lines. As a result, twelve theoretical points Q12, Q23, Q45, Q56, Q78, Q89, Q14, Q47, Q25, Q58, Q36, and Q69 shown in FIG. 6 are set. Furthermore, the theoretical value of each height is calculated. 6 is a plan view of the substrate K1 for explaining a specific example of the arrangement of the measurement points P1 to P9 and the theoretical points Q12, Q23,... At the time when the theoretical point height calculating step S3 is completed in the first embodiment. .

  In the theoretical point setting repetition step S4, the cross-sectional shape in a straight line direction of the substrate is smoothed based on a combination of three or more measurement points and theoretical points arranged in a straight line or three or more theoretical points arranged in a straight line. Approximate with a simple curve, set a new theoretical point between the measurement point and the theoretical point or between the theoretical points, calculate the theoretical value of the height of the new theoretical point using a smooth curve, The setting of a new theoretical point and the calculation of the theoretical value are repeated until the desired number of theoretical points and theoretical values are obtained. In the first embodiment, a total of two arithmetic processes are performed on two straight lines passing through three theoretical points parallel to the short side of the substrate K1.

  In the specific example, paying attention to the straight line L2 (shown in FIG. 6) passing through the three theoretical points Q12, Q45, and Q78, first, from the theoretical value of the height of each theoretical point Q12, Q45, and Q78, the cross section of the substrate K1. The shape is approximated by an arc. Next, a theoretical point Q15 is set at an intermediate point between the theoretical point Q12 and the theoretical point Q45, and a theoretical point Q48 is set at an intermediate point between the theoretical point Q45 and the theoretical point Q78. Third, the theoretical values of the respective heights are calculated assuming that the theoretical point Q15 and the theoretical point Q48 exist on the approximated arc. This calculation processing method is the same as the calculation processing in the theoretical point height calculation step S3 based on the measurement points P4, P5, and P6 described with reference to FIG.

  The same calculation process is performed for the straight line L3 (shown in FIG. 6) passing through the three theoretical points Q23, Q56, and Q89, the theoretical point Q26 and the theoretical point Q59 are set, and the theoretical values of the respective heights are calculated. By the calculation processing so far, the theoretical values of the heights of the 16 theoretical points Q12, Q23,... Can be calculated based on the measured values of the 9 measurement points P1 to P9. As a result, as shown in FIG. 7, the height is measured or calculated at each 5 × 5 lattice point on the substrate K1 and becomes known. 7 is a plan view of the substrate K1 for explaining a specific example of the arrangement of the measurement points P1 to P9 and the theoretical points Q12, Q23,... At the time when the theoretical point setting repetition step S4 is completed in the first embodiment.

  It should be noted that the theoretical point Q15 is set and the theoretical value of the height thereof is calculated in three lines parallel to the straight line passing through the three measurement points P1, P5 and P9 in the diagonal direction of the substrate K1 or the long side of the substrate K1. It can also be performed paying attention to straight lines passing through the theoretical points Q14, Q25, and Q36. However, it is preferable to pay attention to the straight line L2 parallel to the short side of the substrate K1 where the distance between the theoretical points Q12, Q45, and Q78 is the shortest because the approximation error can be reduced.

  In the working point height correction step S5, a correction value for a desired working point height on the substrate is calculated using the measured value of the measuring point and the theoretical value of the theoretical point. In the first embodiment, first, the substrate is divided by a combination of a large number of triangular regions having the measurement points and the theoretical points as vertices, and it is approximated that the substrate is a plane in each triangular region. Next, a correction value for the height of the work point is calculated using a triangular area including the work point.

  FIG. 8 is a diagram illustrating the calculation process performed in the work point height correction step S5 of the first embodiment with a specific example. As shown in FIG. 8, first, a substrate K1 is formed by a combination of 32 measurement points P1 to P9 and 16 theoretical points Q12, Q23,. To divide. Here, in each triangular area, it is approximated that the substrate K1 is a plane. Therefore, a function representing each plane is obtained from the coordinate values and heights of the three vertices. Next, a triangular area including the mounting point is specified from the coordinate value of the mounting point corresponding to the work point. Finally, the height correction value can be calculated on the assumption that the mounting point is on the approximated plane.

  For example, the mounting point W1 in FIG. 8 is included in a triangular area Δ1 (hatched for convenience) with the measurement point P4, the theoretical point Q14, and the theoretical point Q45 as vertices. Therefore, the height correction value Hw1 can be calculated on the assumption that the mounting point W1 exists on a plane approximating the triangular area Δ1. Further, for example, the mounting point W2 in FIG. 8 is included in a triangular area Δ2 (hatched for convenience) having three theoretical points Q58, Q59, and Q89 as vertices. Therefore, the height correction value Hw2 can be calculated on the assumption that the mounting point W2 exists on a plane that approximates the triangular area Δ2.

  When the correction values for the heights of the mounting points of all the components mounted on the board K1 are calculated, the work point height correction step S5 is terminated. Thereafter, the component is mounted on each mounting point on the board K1 using the calculated height correction value.

  Next, the effect of the substrate height correcting method of the substrate working apparatus according to the first embodiment will be described in comparison with the prior art. FIG. 9 is a plan view of a substrate K9 illustrating a conventional height correction method. In the prior art, for example, the height of the substrate K9 is measured at nine measurement points P1 to P9, respectively, and the height of the work point is corrected by approximating a triangular region having the measurement points P1 to P9 as vertices on a plane. It was. In the specific example of FIG. 9, the substrate K9 is divided into eight triangular regions.

  On the other hand, in the substrate height correction method of the substrate working apparatus of the first embodiment, theoretical points Q45 and Q56 are set at the midpoints of the three measurement points P4, P5, and P6 aligned on a straight line, Triangular areas were set by adding theoretical points Q45 and Q56 to measurement points P4, P5 and P6. In the example of FIG. 8, 16 theoretical points Q45 and Q56 are set for 9 measurement points P1 to P9, and finally 32 triangular regions are set. Therefore, compared with the prior art, the number of divisions of the triangular area is four times, and the error when the triangular area is approximated by a plane is reduced, and the height correction accuracy can be improved.

  In addition, the number of measurement points performed by moving the laser height sensor 6 is the same as that in the first embodiment and the conventional technology, and the theoretical value of the theoretical point height can be calculated in a shorter time than actual measurement. It was calculated by processing. For this reason, the time required for height correction does not increase significantly from the prior art. Accordingly, it is possible to suppress a decrease in the throughput of substrate production.

  Further, in the theoretical point height calculation step S3 and the theoretical point setting repetition step S4, the deformation of the substrate K1 is approximated by an arc C1, and in the work point height correction step S5, the triangular area is approximated by a plane and the work points W1, W2 are approximated. Correction values Hw1 and Hw2 are calculated. In other words, the overall deformation state of the substrate K1 is approximated by a smooth sectional curve, and the substrate K1 is locally regarded as a plane, and the height of the desired work point is corrected. Thereby, the height correction accuracy can be improved without complicating the arithmetic processing unnecessarily. In addition, an increase in the time required for height correction can be suppressed, and a decrease in throughput of substrate production can be suppressed.

  In addition, since the cross-sectional shape of the substrate K1 is approximated by the arc C1, the height correction accuracy is better than the conventional technique of approximating with a quadratic function for the upper and lower warpage of the spherical surface having a relatively high occurrence frequency. become.

  Note that the long edge of the rectangular shape of the substrate K1 is held at the reference height H0 by the clamp device. Accordingly, in the measurement point determination step S1, if the six measurement points P1 to P3 and P7 to P9 that are slightly inward from the long side edge are changed and set to neighboring points close to the edge, the measurement point height measurement is performed. In step S2, the measurement by the laser height sensor 6 can be omitted. In this case, the measured value of the height of the six neighboring points is the retained reference height H0.

  In this aspect, the number of measurement points to be measured using the laser height sensor 6 can be reduced from 9 to only the three central measurement points P4, P5, and P6, and the increase in the time required for height correction is further suppressed. Thus, it is possible to further suppress a decrease in substrate production throughput.

  Further, in the theoretical point setting repetition step S4, the number of theoretical points can be increased by performing arithmetic processing a number of times. For example, in the first embodiment, the height is known at each 5 × 5 grid point on the substrate K1, but the number of theoretical points is increased until the height is known at each 9 × 9 grid point. be able to. Then, the number of triangular regions used in the work point height correction step S5 is further increased and the area of each triangular region is further reduced, so that errors caused by plane approximation are reduced.

  In this aspect, since the desired number of theoretical points and theoretical values are obtained in the theoretical point setting repetition step S4, the height correction accuracy can be significantly improved. In addition, the setting of a new theoretical point and the calculation of the theoretical value of the height are all performed by calculation processing, and it is not necessary to add actual measurement using the laser height sensor 6, so the time required for height correction is greatly increased. However, the decrease in throughput of substrate production can be suppressed.

  Next, the substrate height correction method for the substrate working apparatus of the second embodiment will be described mainly with respect to differences from the first embodiment with reference to FIGS. 10 to 12. FIG. 10 is a flowchart illustrating a substrate height correction method for the substrate working apparatus according to the second embodiment. As can be seen by comparing the flowchart of FIG. 10 with that of the first embodiment of FIG. 3, in the second embodiment, a substitute point height measurement step S6 is added before the theoretical point height calculation step S3A. In the second embodiment, for example, even if it is assumed that nine grid measurement points illustrated in FIG. 4 are set, there is actually no circuit pattern at a desired position and measurement points cannot be set as expected. As a countermeasure for this, a substitute point height measurement step S6 is further included.

  In the substitute point height measurement step S6, when the third measurement point arranged in a straight line cannot be set, a substitute point and three auxiliary measurement points are set, and a substitute measurement value of the height of the substitute point is obtained. FIG. 11 is a diagram illustrating the contents of the arithmetic processing performed in the substitute point height measurement step S6 of the second embodiment. In the specific example of FIG. 11, when paying attention to the straight line L4 passing through the two measurement points PA and PB, if there is no third measurement point arranged side by side, first, the substitute point PC is set on the straight line L4. Three auxiliary measurement points Pa1, Pa2, and Pa3 are set around the vicinity of the PC. At this time, the three auxiliary measurement points Pa1, Pa2, and Pa3 are set to positions that can perform height measurement on the circuit pattern and are close to the substitute point PC. Further, it is preferable that the substitute point PC is included inside a triangle having the three auxiliary measurement points Pa1, Pa2, and Pa3 as vertices.

  Next, a larger weight value is assigned to the three auxiliary measurement points Pa1, Pa2, and Pa3 as the distance from the substitute point PC is smaller. The weight value can be a value proportional to the square root of the reciprocal of the distance, for example, and is not limited to this. In general, auxiliary measurement points closer to the substitute point PC often approach the height of the substitute point PC in many cases, and it is appropriate to assign a large weight value. Third, the auxiliary measurement values of the heights of the three auxiliary measurement points Ap1, Ap2, and Ap3 are measured by the laser height sensor 6. Fourth, each auxiliary measurement value is multiplied by the above-described weight value and added to calculate a weighted average value, which is used as a substitute measurement value for the height of the substitute point PC.

  In the next theoretical point height calculation step S3A, the substitute point PC and the substitute measurement value are handled as the third measurement point and the measurement value arranged in the measurement points PA and PB. Subsequent calculation processing contents of the theoretical point repetition step S4 and the work point height correction step S5 are the same as those in the first embodiment. In FIG. 11, even if another measurement point PX exists at a distant position far away from the measurement points PA and PB on the straight line L4, there is a possibility that an error when the cross-sectional shape is approximated increases. Therefore, the distant measurement point PX is not adopted as the third measurement point aligned on a straight line.

  FIG. 12 is a diagram illustrating an application form of the substitute point height measurement step S6 of the second embodiment. In FIG. 12, when paying attention to the straight line L5 passing through the two measurement points PD and PE, when there is no third measurement point arranged, first, the substitute point PF is set on the straight line L5, and the vicinity of the substitute point PF. Two auxiliary measurement points Pa4 and Pa5 are set around. The second measurement point PE is also used as the third auxiliary measurement point. At this time, the substitute measurement value of the height of the substitute point PF can be calculated by the weighted average value of the auxiliary measurement values of the two auxiliary measurement points Pa4 and Pa5 and the measurement value of the measurement point PE.

  In the substrate height correcting method and its application mode of the substrate working apparatus according to the second embodiment, the third measurement point on a straight line due to restrictions on the structure of the substrate, for example, restrictions on the arrangement of circuit patterns capable of measuring the height. Even if it cannot be set, height correction accuracy can be improved.

  Next, the substrate height correction method for the substrate working apparatus of the third embodiment will be described mainly with respect to differences from the first and second embodiments with reference to FIGS. 13 and 14. The third embodiment is a method in which four or more measurement points are set on a straight line, and the cross-sectional shape of the substrate can be approximated by two or more smooth curves. FIG. 13 is a plan view of the substrate K2 for explaining a specific example of the arrangement of the measurement points P11 to P22 in the third embodiment. FIG. 14 is a diagram illustrating the contents of arithmetic processing performed in the theoretical point height calculating step of the third embodiment. In FIG. 14, large arrows indicate measurement points, and small arrows indicate theoretical points.

  As shown in FIG. 13, twelve measurement points P11 to P22 are set in a 3 × 4 lattice pattern on a rectangular substrate K2. Here, four measurement points P15 to P18 are arranged on the central straight line L6 parallel to the long side of the substrate K2, and the measurement values of the heights are respectively obtained. Therefore, in the theoretical point height calculating step S3, the cross-sectional shape of the substrate K3 is set to the arc C2, at the three left measurement points P15, P16, P17 and the three right measurement points P16, P17, P18 in FIG. It can be approximated by C3.

  In FIG. 14, an arc C <b> 2 indicating an upward warp is obtained based on the three measurement points P <b> 15, P <b> 16 and P <b> 17. On the other hand, based on the three measurement points P16, P17, and P18, an arc C3 indicating a downward warp is obtained. For the theoretical point QL set at the intermediate point between the measurement point P15 and the measurement point P16, the theoretical value of the height is calculated assuming that the theoretical point QL exists on the arc C2 as in the first embodiment. Further, the theoretical value of the height is calculated assuming that the theoretical point QN set at the intermediate point between the measurement point P17 and the measurement point P18 is on the arc C3.

  However, between the measurement point P16 and the measurement point P17, the cross-sectional shape of the substrate K2 is approximated by two arcs C2 and C3, and the two arcs C2 and C3 do not coincide with each other. At this time, in the theoretical point height calculation step of the third embodiment, an average curve C4 passing between the two arcs C2 and C3 is obtained between the measurement point P16 and the measurement point P17. Then, a theoretical value of height is calculated for the theoretical point QM set at the intermediate point between the measurement point P16 and the measurement point P17, assuming that the theoretical point QM exists on the average curve C4.

  The average curve C4 may be approximated by a simple straight line when there is a mismatch between the upper and lower warps. In other words, in the above example, the measurement point P16 and the measurement point P17 may be approximated by a straight line. Further, the average curve C4 can be a curve passing through the intermediate height of the two arcs C2 and C3, and other approximation methods may be used. Thus, even in the boundary region where the upper warp and the lower warp are joined, the theoretical value of the height can be calculated by setting the theoretical point QM.

  In addition, when the two measurement points are approximated by two upward-curved arcs, or approximated by two downward-curved arcs, and the radii of the arcs do not coincide with each other, the third The theoretical point height calculation step of the embodiment can be applied. In this case, for example, an average curve can be obtained by obtaining an average radius of two types of arc radii.

  In the substrate height correcting method and its application of the substrate working device according to the third embodiment, four or more measurement points are set on a specific straight line, and the deformation is more complicated than a simple upper warp or lower warp, for example, It is possible to accurately approximate the undulation-like deformation that the unevenness joins. Furthermore, it is possible to accurately approximate a region where the deformation state changes, for example, a boundary region in the middle of changing from the convex deformation region to the concave deformation region, such as between the measurement point P16 and the measurement point P17 described above.

  Next, a substrate height correcting method for a substrate working apparatus according to the fourth embodiment will be described with reference to FIGS. In the fourth embodiment, before starting the lot production of the substrate, the measurement points are determined by taking detailed steps in the measurement point determination step S1. When a substrate is mass-produced in lot units, a large number of substrates in the same lot generally exhibit a similar deformation state. Therefore, if a sample substrate is selected from the same lot and the tendency of the deformation state is confirmed in advance, the number and position of the measurement points can be optimized, and height correction accuracy can be secured even if the number of measurement points is narrowed down. It is done. The measurement point determination step S1 of the fourth embodiment is based on this concept.

  FIG. 15 is a flowchart illustrating the details of the measurement point determination step S1 in the fourth embodiment. In the fourth embodiment, the measurement point determination step S1 includes a sample measurement step S11, a comparison point calculation step, and a validity determination step. In the flowchart of FIG. 15, steps S12 and S13 correspond to comparison point calculation steps, and steps S14 to S18 correspond to validity determination steps.

  In the sample measurement step S11, a sample substrate is selected from a large number of substrates in the same lot, and sample measurement values that are the heights of a large number of sample measurement points on the sample substrate are measured. The purpose of this step S11 is to confirm the deformation state of the sample substrate with high accuracy by actual measurement and grasp the tendency of the deformation of the substrate in the same lot. Therefore, it is preferable that the number of sample measurement points is large enough to reliably confirm the deformation state of the sample substrate. The position of the sample measurement point is not particularly limited, but is preferably a grid-like arrangement in order to simplify subsequent calculation processing. Note that the measurement itself can be performed using the laser height sensor 6 of the component mounting machine 1, or may be performed using another height measuring device outside the component mounting machine 1.

  FIG. 16 is a plan view of the sample substrate KS schematically showing the measurement result of the sample measurement step S11 in the fourth embodiment. In the illustrated measurement example, 25 sample measurement points in a 5 × 5 grid are set on a rectangular sample substrate KS. The sample measurement value at each sample measurement point is displayed by being divided into symbols according to the magnitude of the value. Specifically, a small value of the sample measurement value is displayed as a white circle, a medium value of the sample measurement value is displayed as a double circle, and a large value of the sample measurement value is displayed as a black circle. That is, it is displayed that the double circle sample measurement point is higher than the white circle sample measurement point, and the black circle sample measurement point is higher. In the measurement example of FIG. 16, it can be seen that the cross-sectional shape of the sample substrate KS is warped in a straight line L7 parallel to the short side of the sample substrate KS. Note that the sample measurement values can be displayed in different colors on a color display device provided in the component mounting machine 1, or the numerical values of the sample measurement values themselves may be displayed as a list.

  In the next step S12, a large number of sample measurement points are divided into reference points and comparison points, and the reference points are initialized. The reference points are provisional decisions and are not fixed, but are sequentially changed in the subsequent arithmetic processing. There is no particular restriction on the initial setting method of the reference points. For example, many sample measurement points are selected every other point.

  FIG. 17 is a plan view of the sample substrate KS schematically showing a state in which a large number of sample measurement points are divided into reference points and comparison points in the fourth embodiment. In the illustrated example, nine reference points are selected for every other 25 sample measurement points, and the original symbols are displayed as they are. The remaining 16 points are used as comparison points, and white circles, double circles, and black circles are changed to white triangles, double triangles, and black triangles, respectively.

  In the next step S13, an estimated value of the height of the comparison point is calculated using the sample measurement value of the reference point. In other words, assuming that the height of the comparison point is unknown, the height of the comparison point is estimated using only the sample measurement value of the reference point. At this time, it is preferable to use the same arithmetic processing method as the method of estimating and correcting the height of the work point during the mass production of the substrate. In the fourth embodiment, the reference point and the sample measurement value thereof are regarded as the measurement point and the measurement value, the comparison point and the estimated value thereof are regarded as the attachment point and the correction value, and the theoretical point height calculation step S3 of the first embodiment is performed. Then, the theoretical point setting repetition step S4 and the working point height correction step S5 are performed.

  In the next step S14, the correlation between the sample measured value at the comparison point and the estimated value estimated in step S13 is grasped. Specifically, the difference value is obtained by subtracting the estimated value from the sample measurement value at the comparison point. FIG. 18 is a plan view of the sample substrate KS schematically showing the difference value at the comparison point in the fourth embodiment. In the illustrated example, the reference points are displayed as white circles, and the comparison points are displayed as squares. Furthermore, the quadrangle that displays the comparison points is divided into symbols corresponding to the magnitudes of the difference values. Note that the difference values of the comparison points can be displayed in different colors, or the numerical values themselves can be displayed as a list.

  In the next step S15, the validity of the grasped correlation is evaluated. Specifically, the difference value is determined by comparing with a predetermined allowable value. The predetermined allowable value is set in consideration of a margin in consideration of a range in which the board height error does not affect the work quality of component mounting. In general, the limit of the allowable substrate height error is about 2 mm. However, even if a large number of substrates in the same lot show a similar deformation tendency, the absolute value of the deformation changes, and a measurement error or an approximation error occurs due to the height correction of the work point. For this reason, it is preferable to set the predetermined allowable value considerably smaller than 2 mm.

  In step S15, it is determined that the correlation is insufficient when the difference value exceeds a predetermined allowable value, and the process proceeds to step S16. In step S16, the reference point is changed or increased, and the process returns to step S13.

  In the specific example shown in FIG. 18, a white square indicates a valid point where the difference value is within the allowable value, and a double square indicates an invalid point where the difference value slightly exceeds the allowable value. The squares in (2) indicate the invalid points where the difference value greatly exceeded the allowable value. Therefore, it is determined that the correlation is insufficient due to the presence of three invalid points, and the process proceeds to step S16. In step S16, the reference point is changed or increased so as to eliminate the invalid point, and the process returns to step S13.

  In step S15, it is determined that the correlation is excessive when all the difference values are significantly lower than the allowable value, and the process proceeds to step S17. In step S17, the reference point is decreased and the process returns to step S13. In step S15, when all the difference values are below the allowable value and it is difficult to reduce the reference points, it is determined that the correlation is appropriate, and the process proceeds to step S18. In step S18, the reference point when it is determined that the correlation is appropriate is determined as the measurement point, and the measurement point determination step S1 is terminated.

  When the determination is lost in step S15, the setting of the reference point is changed and steps S13 to S15 are repeated to reliably determine whether or not the approximate correlation is appropriate. A reliable way to eliminate the invalid point is to change the sample measurement point from the comparison point to the reference point. However, increasing the reference points is contrary to the goal of narrowing down the number of measurement points. Therefore, it is preferable to repeat a certain amount of trial and error so that the correlation is appropriate with as few reference points as possible.

  It should be noted that automatic calculation processing by the control computer can be performed by adopting a method in which a predetermined allowable value is set and compared with the difference value, but is not limited thereto. For example, the operator may determine the validity of the correlation based on the displays of FIGS.

  In the fourth embodiment, after the measurement point is determined in the measurement point determination step S1, the process from the measurement point height measurement step S2 to the work point height correction step S5 described in the first embodiment is performed. The present invention is not limited to this, and the conventional height correction method described with reference to FIG. 9 can be performed after the measurement point determination step S1.

  According to the substrate height correction method of the substrate working apparatus of the fourth embodiment, the deformation state of the sample substrate is confirmed in advance with high accuracy, and as few measurement points as possible are approximated with sufficient accuracy. decide. Therefore, it is possible to optimize the measurement position while limiting the number of height measurement points for a large number of substrates exhibiting similar deformation tendencies within the same lot, and the deformation of the substrate can be approximated with sufficient accuracy. Thereby, the number of height measurement points at the time of substrate mass production can be limited, and the throughput of substrate production is improved.

  Furthermore, based on the magnitude of the difference value obtained by subtracting the estimated value from the sample measurement value at the comparison point, it is objectively determined whether or not the approximate correlation of the deformation of the sample substrate is appropriate. The number of height measurement points and the measurement position can be reliably optimized. In addition, since it is possible to automatically determine the appropriateness of the correlation, the labor of the operator is reduced.

  In addition, when the deformation of the sample substrate is approximated based on the sample measurement value of the reference point limited in the comparison point calculation step, the estimated value of the comparison point is calculated by the same arithmetic processing method as in the substrate mass production. As a result, the deformation method approximation method is consistent between the sample substrate for determining the validity of measurement points and many substrates at the time of mass production, and even if the number of height measurement points at the time of mass production is limited, the deformation of the substrate Can be approximated with sufficient accuracy.

  In addition, in the validity determination step (steps S14 to S19), one or more of the data group consisting of the sample measurement value, the estimated value, and the difference value is displayed by being color-coded or symbol-coded according to the magnitude of the value. Thereby, even when the operator determines the approximate correlation, the determination can be easily made visually, and the troublesome and delicate determination is reduced.

  The sample measurement step S11 can also be performed outside the component mounter 1. Furthermore, it is not always necessary to execute and control the detailed steps S11 to S18 in the measurement point determination step S1 by the control computer of the component mounting machine 1, and another computer may be used. At this time, another height measuring device having a different measurement method from the laser height sensor 6 of the component mounting machine 1 can be used. Moreover, since it can carry out offline without using the component mounting machine 1 in a board | substrate production line, it does not affect production work. In addition, the deformation state of the sample substrate can be confirmed with extremely high accuracy by taking a sufficient time to measure a large number of sample measurement points.

  In addition, in the work point height correction step S5 of each embodiment, a correction method other than approximating the triangular area with a plane can be used. Also in this case, the height correction accuracy can be improved by treating the theoretical value of the height of the theoretical point in the same manner as the actual measurement value. Further, the height measuring device is not limited to the laser height sensor 6, and a sensor of another measuring method may be used. Various other applications and modifications are possible for the present invention.

  The board height correcting method for a board working device according to the present invention can be used for a component mounting work of a component mounting machine, and can also be used for a work of applying an adhesive to a board with the component mounting machine. Furthermore, the substrate height correction method of the substrate working apparatus according to the present invention is used for a drawing type solder printing machine having a dispenser device or an ink jet device and for dropping cream solder onto the substrate or injecting liquid solder. it can.

1: Component mounting machine (PCB work equipment)
2: substrate transfer device 3: component supply device 4: component transfer device 5: component camera 6: laser height sensor (height measurement device)
9: Machine stand L1: Laser light L2, L3: Reflected laser light K, Ka, Kb, K1, K2, K9: Substrate KS: Sample substrate H0: Reference height Ha, H1, H2, H3: Height P1 to P9 , P11 to P22, PA, PB, PD, PE, PX: measurement point PC, PF: substitute point Pa1 to Pa5: auxiliary measurement point Q12 to Q89, QL, QM, QN: theoretical points L1 to L7: straight lines C1 to C3 : Arc C4: Average curve W1, W2: Mounting point (working point) Δ1, Δ2: Triangle area

Claims (11)

A measurement point height measurement step of holding the substrate in a horizontal posture by the substrate holding device of the substrate working device, and measuring the measured values of the plurality of measurement points on the substrate by the height measurement device,
Based on three or more measurement points arranged on a straight line, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating a theoretical value of the height of the point using the smooth curve;
Based on a combination of three or more measurement points and theoretical points arranged on a straight line or three or more theoretical points arranged on a straight line, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve, A new theoretical point is set between the measurement point and the theoretical point or between the theoretical points, and the theoretical value of the height of the new theoretical point is calculated using the smooth curve, and desired A theoretical point setting iteration step that repeats setting a new theoretical point and calculating a theoretical value until a theoretical point and a theoretical value of the quantity are obtained;
Using the measurement value of the measurement point and the theoretical value of the theoretical point, a work point height correction step for calculating a correction value for a desired work point height on the substrate;
A substrate height correcting method for a substrate working device having A measurement point height measurement step of holding the substrate in a horizontal posture by the substrate holding device of the substrate working device, and measuring the measured values of the plurality of measurement points on the substrate by the height measurement device,
Based on three or more measurement points arranged on a straight line, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating a theoretical value of the height of the point using the smooth curve;
Using a measurement value of the measurement point and a theoretical value of the theoretical point, a work point height correction step of calculating a correction value of a desired work point height on the substrate,
When there is no third measurement point arranged when focusing on a specific straight line, a substitute point to replace the third measurement point is set on the specific straight line before the theoretical point height calculation step. , Three auxiliary measurement points are set around the substitute point and a larger weight value is assigned as the distance from the substitute point is smaller, and the height measurement device determines the height of the three auxiliary measurement points. A substitute point height measurement step is further provided in which a weighted average value obtained by measuring auxiliary measurement values, multiplying each auxiliary measurement value by the weight value, and adding the weight values is used as a substitute measurement value of the substitute point height. And
A substrate height correction method for a substrate working apparatus that treats the substitute point and the substitute measurement value as the third measurement point and measurement value in the theoretical point height calculation step. A measurement point height measurement step of holding the substrate in a horizontal posture by the substrate holding device of the substrate working device, and measuring the measured values of the plurality of measurement points on the substrate by the height measurement device,
Based on three or more measurement points arranged on a straight line, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating a theoretical value of the height of the point using the smooth curve;
Using a measurement value of the measurement point and a theoretical value of the theoretical point, a work point height correction step of calculating a correction value of a desired work point height on the substrate,
In the theoretical point height calculating step,
When paying attention to a specific straight line, there are a plurality of combinations of the three or more measurement points, the cross-sectional shape between the two specific measurement points can be approximated by a plurality of smooth curves, and the plurality of smooth points An average curve passing between the plurality of smooth curves, and a theoretical value of a theoretical point height between the two specific measurement points is calculated as the average value. Substrate height correction method for a substrate working device, which is calculated using a typical curve. A measurement point height measurement step of holding the substrate in a horizontal posture by the substrate holding device of the substrate working device, and measuring the measured values of the plurality of measurement points on the substrate by the height measurement device,
Based on three or more measurement points arranged on a straight line, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating a theoretical value of the height of the point using the smooth curve;
Using a measurement value of the measurement point and a theoretical value of the theoretical point, a work point height correction step of calculating a correction value of a desired work point height on the substrate,
In the measuring point height measuring step,
The substrate holding device holds the specific location of the substrate at a reference height, sets a nearby point close to the specific location as a part of the measurement point, and the measured value of the height of the nearby point is the height measurement. A method for correcting a substrate height of a work apparatus for a substrate, wherein the reference height is set without performing measurement by an apparatus. In claim 2 , in the measurement point height measurement step,
It said retaining certain portion of the substrate by the substrate holding device in reference height, set the neighbor point closer to the specific position in the part of the previous SL auxiliary measurement point, auxiliary measurements of the height of the neighboring points A method for correcting a substrate height of a substrate working apparatus that uses the reference height without performing measurement by the height measuring device. A measurement point height measurement step of holding the substrate in a horizontal posture by the substrate holding device of the substrate working device, and measuring the measured values of the plurality of measurement points on the substrate by the height measurement device,
Based on three or more measurement points arranged on a straight line, the cross-sectional shape in a straight line direction of the substrate is approximated by a smooth curve, and a theoretical point is set between the three or more measurement points. A theoretical point height calculating step of calculating a theoretical value of the height of the point using the smooth curve;
Using a measurement value of the measurement point and a theoretical value of the theoretical point, a work point height correction step of calculating a correction value of a desired work point height on the substrate,
Further comprising a plurality of pre-determined measurement points determined step advance a measurement point on the substrate before Symbol measurement point height measurement step, the measurement point determination step,
Elected sample substrate from a number of the substrate in the same lot, a sample measuring step of measuring the sample measurements is the height of the large number of samples measurement point on the sample substrate,
A comparison point calculating step of dividing the multiple sample measurement points into a reference point and a comparison point, and calculating an estimated value of the height of the comparison point using the sample measurement value of the reference point;
Compare the correlation between the sample measurement value and the estimated value at the comparison point, and when the correlation is determined to be insufficient, change or increase the reference point and return to the comparison point calculation step, When it is determined that the correlation is excessive, the reference point is decreased and the process returns to the comparison point calculation step. When the correlation is determined to be appropriate, the reference point is determined as the measurement point. A substrate height correction method for a substrate working device, comprising: a sex determination step. In claim 6 , in the validity determination step,
Subtracting the estimated value from the sample measurement value at each comparison point to obtain a difference value, and determining that the correlation is insufficient when any difference value exceeds a predetermined allowable value, It is determined that the correlation is excessive when a difference value is significantly below the tolerance, and the correlation is when all the difference values are below the tolerance and it is difficult to reduce the reference point. The board height correction method of the board work equipment which judges that is appropriate. 8. The comparison point calculation step according to claim 6 , wherein the reference point and the sample measurement value thereof are regarded as the measurement point and the measurement value, and the comparison point and the estimated value are regarded as the working point and the correction value. Te, substrate height correction method of the working device substrate for performing the theoretical point height calculation step and the working point height correction step. In any one of Claims 6-8 , it consists of at least 1 type of the difference value calculated | required by subtracting the said estimated value from the said sample measured value, the said estimated value, and the said sample measured value in the said validity judgment step. A substrate height correction method for a substrate working device that displays one or more data groups in a color-coded or symbol-coded manner according to the magnitude of the value. 10. The substrate according to claim 1 , wherein in the working point height correction step, the substrate is divided by a combination of a large number of triangular regions having the measurement points and the theoretical points as vertices, and each of the triangular regions. in approximates the substrate is planar, substrate height correction method of a substrate for a working device for calculating a correction value of the height of the working point by using the triangular area in which the working point is included. The substrate height of the working apparatus for a substrate according to any one of claims 1 to 10 , wherein in the theoretical point height calculation step, the cross-sectional shape is approximated by an arc based on three measurement points arranged in a straight line. Correction method.

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