KR20240042042A - Work height measuring device and mounting board inspection device using it - Google Patents

Abstract

The work height measuring device includes an imaging unit that captures an image of the work, a line light projection unit that has a projection optical axis having a predetermined intersection angle with respect to the imaging optical axis, and is capable of irradiating line light from a plurality of directions with respect to the work, and the above-described line light projection unit. It is provided with a scan driving unit that moves the imaging unit and the line light projection unit to scan the workpiece, and a measurement unit that obtains height data of the workpiece by an optical cutting method based on the image acquired by the scanning. The measurement unit irradiates the line light to the workpiece from a predetermined irradiation direction to perform a first scan, and determines whether or not there is a missing portion in the height data of the workpiece in the height data obtained based on the image acquired through the first scan. is determined, and when the missing part is detected, a second scan is performed in which the line light is irradiated in a direction different from that of the first scan.

Description

Work height measuring device and mounting board inspection device using it

The present invention relates to, for example, a device for measuring the height of a work such as an electronic component mounted on a board and a mounted board inspection device using the same.

For example, in a production line of component mounting boards in which electronic components (works) are mounted on a board, it is necessary to inspect whether the electronic parts are mounted on the board as designed. By measuring the height of a component mounting board, it is possible to detect mounting problems of electronic components, such as component lifting, mounting position misalignment, and mounting leakage. The optical cutting method is known as a non-contact method for measuring the height of a workpiece. In the optical cutting method, a workpiece to which line light is irradiated at an angle is imaged, and the height of the workpiece is determined from the captured image using the principle of triangulation. Patent Document 1 discloses a device for measuring the three-dimensional shape of a workpiece using an optical cutting method. The device of Patent Document 1 includes a mechanism for rotating an optical cutting probe equipped with a line light source and an imaging camera.

When measuring the height of a workpiece, a scan is performed to take multiple images while moving the line light source and the imaging camera horizontally with respect to the workpiece. Height data is obtained from each image obtained by scanning, and by combining these height data, the shape of the work can be measured. Here, for example, when a plurality of workpieces are arranged at high density or a low-height workpiece is arranged adjacent to a high-height workpiece, the line light to be irradiated to the target workpiece is directed to the adjacent workpiece. There is something about being shaded. In this case, a problem arises in which the height of the target work cannot be accurately measured.

Japanese Patent Publication No. 2015-72197

The purpose of the present invention is to provide a work height measuring device that can accurately measure the height of a workpiece regardless of its arrangement state, and a mounting board inspection device using the same.

A workpiece height measuring device according to one aspect of the present invention has an imaging optical axis in a vertical direction, an imaging unit that captures an image of a workpiece, and a projection optical axis having a predetermined intersection angle with respect to the imaging optical axis, and has a plurality of projection optical axes with respect to the workpiece. A line light projection unit capable of irradiating line light from an orientation, a scan driver for moving the image pickup unit and the line light projection unit to scan a workpiece, and controlling the scan driver to execute the scan, a measuring unit that obtains height data of the workpiece by an optical cutting method based on an image acquired by scanning; the measuring unit irradiates the line light to the workpiece from a predetermined irradiation direction to perform a first scan; In the height data obtained based on the image acquired in the first scan, the presence or absence of a missing part of the height data of the work is determined, and when the missing part is detected, the irradiation direction of the line light is set to an orientation different from that of the first scan. Run the second scan.

A mounted board inspection device according to another aspect of the present invention includes an inspection stage into which a mounted board with components mounted is loaded, and a workpiece height measurement device that measures the height of a component on the mounted board loaded into the test stage as the workpiece. Equipped with equipment.

1 is a block diagram showing the configuration of a mounting board production line equipped with a work height measuring device according to the present invention as an external inspection machine.
2(A) to 2(C) are schematic diagrams showing a method of measuring component height by optical cutting.
Figures 3(A) and (B) are diagrams illustrating the shortcomings of part height measurement by optical cutting, and Figure 3(C) is a diagram showing the solution.
Figure 4 is a perspective view schematically showing the hard configuration of the external inspection device.
Figure 5 is a block diagram showing the electrical configuration of the external inspection device.
Figures 6(A) to (C) are perspective views showing the rotation state of the head equipped with the camera unit and the line light source.
Figure 7 is a perspective view showing a head according to a modified example.
8(A) to 8(D) are schematic diagrams for explaining component height measurement according to the first embodiment.
9(A) to 9(D) are schematic diagrams for explaining component height measurement according to the first embodiment.
10(A) to 10(D) are schematic diagrams for explaining component height measurement according to the second embodiment.
11(A) to 11(C) are schematic diagrams for explaining component height measurement according to the second embodiment.
Fig. 12 is a flowchart showing scan direction determination processing in component height measurement according to the second embodiment.
13(A) to 13(E) are schematic diagrams for explaining component height measurement according to the third embodiment.
14(A) and 14(B) are schematic diagrams for explaining component height measurement according to the fourth embodiment.
15(A) and 15(B) are schematic diagrams for explaining component height measurement according to the fourth embodiment.
Fig. 16 is a flowchart showing scan area determination processing in component height measurement according to the fourth embodiment.
17(A) to 17(C) are schematic diagrams for explaining component height measurement according to the fifth embodiment.
18(A) to 18(C) are schematic diagrams for explaining component height measurement according to the fifth embodiment.
Fig. 19 is a flowchart showing the scanning direction determination process for each component in component height measurement according to the fifth embodiment.
20(A) to 20(C) are schematic diagrams for explaining component height measurement according to a modification of the fifth embodiment.
Fig. 21 is a flowchart showing the scanning direction determination process for each component in component height measurement according to a modification of the fifth embodiment.
22(A) to 22(D) are schematic diagrams for explaining component height measurement according to the sixth embodiment.
Fig. 23 is a flowchart showing the creation process of high-definition part height data in part height measurement according to the sixth embodiment.
24(A) and 24(B) are diagrams showing a modified example of scanning.
Fig. 25 is a diagram showing a modified example of image data acquisition.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention will be described in detail based on the drawings. The workpiece height measuring device according to the present invention can be widely applied to measuring the shape of workpieces of various industrial products, semi-finished products, machine parts, electronic parts, food, agricultural products, etc. In the embodiment shown below, an example in which height measurement is performed using a component mounted on a board as a workpiece will be described. Here, an example is shown in which the work height measuring device according to the present invention is applied to an external inspection of a board after component mounting in a production line of a mounted board.

[Mounting board production line]

Figure 1 is a block diagram showing the configuration of a mounting board production line 1 for mounting electronic components on a printed board. The mounting substrate production line 1 includes a printing machine 11, a print inspection machine 12, a component mounting machine 13, a reflow furnace 14, and An external appearance inspection device 15 (work height measurement device/mounted substrate inspection device) is provided.

The printer 11 applies solder to the pad portion of the printed board. For example, the printer 11 overlaps a mask with an open solder application portion on a printed circuit board, and applies cream solder from the mask. The print inspection device 12 inspects whether the location or amount of solder applied to the printed board is appropriate. The component mounting machine 13 is equipped with a component mounting head and mounts required components on a printed circuit board. The reflow furnace 14 heats the printed board on which the components are mounted, melts the solder, and fixes the components to the board.

The appearance inspection device 15 inspects whether the electronic components are mounted on the printed board in the correct position without defects. Specifically, the appearance inspection machine 15 inspects the electronic components mounted on the printed board for misalignment, component lifting, mounting leakage, soldering defects, etc. For these inspections, it is sufficient to inspect the appearance of the mounting board, that is, measuring the height of the mounting board. The appearance inspection device 15 detects mounting defects by comparing the height data obtained from the height measurement with the design data of the board. The appearance inspection device 15 of this embodiment performs the above height measurement using an optical cutting method.

[Height measurement by optical cutting method]

With reference to FIGS. 2(A) to 2(C), an explanation will be added regarding the height measurement by the optical cutting method employed by the appearance inspection machine 15. As shown in Fig. 2(A), the measurement target is a component C (work) mounted on the substrate surface PS of the mounting substrate P. Although the hardware configuration will be described in detail later, the appearance inspection device 15 is equipped with a camera unit 4 (imaging unit) and a line light source 5 (line light projection unit).

The camera unit 4 has an imaging optical axis AX in a direction perpendicular to the substrate surface PS and captures an image of the component C. The line light source 5 has a projection optical axis having a predetermined intersection angle θ with respect to the imaging optical axis AX, and emits line light SL along the projection optical axis. Line light (SL) is irradiated to the component (C) to be measured. In this embodiment, the unit carrying the camera unit 4 and the line light source 5 is provided with a mechanism for rotating around the axis of the imaging optical axis AX. With the above mechanism, the line light source 5 can irradiate the line light SL from a plurality of directions to the component C to be measured.

FIG. 2(B) shows an image IM acquired by the camera unit 4 at a certain scan position SC1 where the line light SL is irradiated to the component C. When the line light SL is irradiated to the area including the component C, reflected light RL1 from the substrate surface PS around the component C and reflected light RL2 from the upper surface of the component C Images are captured with this camera unit 4. Since the line light SL is incident light and the component C has a height, the reflected light RL1 and RL2 are observed at different positions of the X coordinate on the image IM. Specifically, the reflected light RL1 is shown at coordinates (x11), and the reflected light RL2 is shown at coordinates (x12) downstream of the scan direction from the coordinates (x11).

The case where the line light (SL) is irradiated to the point P0 in FIG. 2(A) is treated as a point with height = 0 in the calculation. Then, as shown in FIG. 2(C), from the principle of triangulation using the intersection angle θ, height data such as h1 as the height of the coordinate (x11) and h2 as the height of the coordinate (x12) can be obtained. Thereafter, the camera unit 4 and the line light source 5 are moved from the scan position SC1 to the downstream side in the scanning direction, while the camera unit 4 sequentially captures images at the scan positions SC2 and SC3. As a result, height data of coordinates (x21, x22) are acquired at the scan position SC2, and height data of coordinates (x31, x32) are acquired at the scan position SC3. Needless to say, the actual scan pitch is much narrower than the drawing example.

By integrating a plurality of height data acquired by scanning, three-dimensional shape data of the part C can be obtained. Additionally, the height data acquired at one scan position (SC1, SC2, SC3) is based on the results of reflected light (RL1, RL2) being irradiated to different X coordinate positions. For this reason, in data integration, for example, the height data of the coordinates (x12) obtained in the area of the component C at the scan position SC1 and the coordinates obtained in the area of the substrate surface PS at the subsequent scan position A height table that adjusts the height data of (x12) is created.

Figures 3(A) and (B) are diagrams illustrating the shortcomings of part height measurement using the optical cutting method. The projection optical axis of the line light SL by the line light source 5 is inclined with respect to the vertical axis. For this reason, when the line light SL is irradiated to the component C having a height as shown in FIG. 3(A), the shadow portion SH which becomes the shadow of the component C and is not covered by the line light SL occurs. Since reflected light with a predetermined brightness does not enter the camera unit 4 in the area of this shadow portion SH, height measurement cannot be performed. FIG. 3(B) is a diagram showing the height data measurement results of the mounting substrate P shown in FIG. 3(A). Although the height of the component C and the substrate surface PS can be measured, the area of the shadow portion SH becomes a missing portion of the height data.

Figure 3(C) is a diagram showing a solution for preventing the above-mentioned height data missing portion from occurring. As the line light source 5, a first line light source 5A and a second line light source 5B arranged oppositely in the scanning direction F are used. The first line light source 5A irradiates the first line light SL1 toward the substrate surface PS at a predetermined crossing angle θ. The second line light source 5B is arranged in the opposite direction to the first line light source 5A across the imaging optical axis AX. The second line light source 5B transmits the second line light SL2 to the substrate surface PS from a direction 180 degrees different from the first line light SL at the same intersection angle θ as that of the first line light SL1. Investigate towards.

By using the second line light SL2, illumination of the shadow portion SH becomes possible. By combining the height measurement result using the first line light SL1 and the height measurement result using the second line light SL2, missing portions of the height data can be eliminated. However, even when a pair of line light sources 5A and 5B is used, missing portions of height data may occur. In this embodiment, height measurement is possible for height data missing portions that cannot be resolved even when a pair of line light sources 5A and 5B are used.

[Description of device configuration]

FIG. 4 is a perspective view schematically showing the hard configuration of the external inspection device 15, and FIG. 5 is a block diagram showing the electrical configuration of the external inspection device 15. The appearance inspection device 15 includes a measuring device main body 2, a control device 3 (measuring section), and a server device 30. The measuring device main body 2 performs a height measurement operation of the mounting board P. The measuring device main body 2 includes a base 21, a moving frame 22, a Y-axis moving mechanism 23 (scan driver/second moving mechanism), and an X-axis moving mechanism 24 (scan driving section/first moving mechanism). ), slider 25, and head 25H. The head 25H is equipped with the above-described camera unit 4 and line light source 5.

The base 21 is a flat frame stand that supports the Y-axis movement mechanism 23 and serves as the measurement stage 21S of the mounting substrate P. A mounted board P to be inspected for appearance is brought in from the reflow furnace 14 to the measurement stage 21S by a conveyor not shown, and the mounted board P is taken out after the inspection. The moving frame 22 is a door-shaped frame extending in the X direction and moves in the Y direction above the base 21. The moving frame 22 maintains the head 25H through the slider 25.

The Y-axis moving mechanism 23 and the The Y-axis moving mechanism 23 is arranged in pairs at both ends of the base 21 in the X direction, and moves the moving frame 22 holding the head 25H (camera unit 4 and line light source 5) in the Y direction. It is a mechanism for horizontal movement (a second movement direction perpendicular to the first movement direction and the horizontal plane). The Y-axis movement mechanism 23 includes a Y-axis motor 231 made of a servomotor or the like, and a Y-axis ball screw shaft (not shown) connected to the Y-axis motor 231. The Y-axis ball screw shaft is screwed to a ball nut attached to the moving frame 22. The X-axis moving mechanism 24 is installed on the moving frame 22 and is a mechanism that horizontally moves the head 25H in the X direction (first moving direction). The X-axis movement mechanism 24 includes an X-axis motor 241 and an X-axis ball screw shaft (not shown) connected to the X-axis motor 241.

The slider 25 is a plate material that holds the head 25H, and is movable in the X direction (scanning direction) with respect to the moving frame 22. The X-axis ball screw shaft is screwed to a ball nut attached to the slider (25). The slider 25 moves in the X direction along the moving frame 22 when the X-axis motor 241 rotates the X-axis ball screw shaft. Meanwhile, the moving frame 22 moves in the Y direction by the Y-axis motor 231 rotating the Y-axis ball screw shaft. Accordingly, the head 25H held by the slider 25 can be moved in the XY direction by the Y-axis moving mechanism 23 and the X-axis moving mechanism 24.

The head 25H includes a camera unit 4 that measures the height of the component C, a pair of line light sources 5 (first line light source 5A and second line light source 5B), and a support plate 251. ), a light source holder 51, and a rotation mechanism 6. The support plate 251 is a plate extending in the Y direction from the slider 25 and rotatably supports the camera unit 4 and the line light source 5 around the imaging optical axis AX. The light source holder 51 is a wing-shaped support frame integrated with the camera unit 4, and supports the first line light source 5A with one wing piece and the second line light source 5B with the other wing piece. I'm doing it. The rotation mechanism 6 is mounted on the support plate 251 and is a mechanism that rotates the camera unit 4 and the line light source 5 together around the imaging optical axis AX. Additionally, the rotation mechanism 6 may be a mechanism that independently rotates the light source holder 51 holding the camera unit 4 and the line light source 5.

The control device 3 controls various operations of the measuring device main body 2. Specifically, the control device 3 controls the Y-axis moving mechanism 23 and the Based on the image, height data of the component C mounted on the mounting substrate P is obtained by optical cutting. The server device 30 relays data transmission between the control device 3 and the measurement device main body 2.

Referring to FIG. 5, a description of the electrical configuration of the appearance inspection device 15 is added. Additionally, in FIG. 5, description of the server device 30 is omitted. The measuring device main body 2 includes a Z-axis motor 261 and an R-axis motor 61 as elements not shown in FIG. 4 . The Z-axis motor 261 is a driving source that lifts and moves the head 25H in the Z-axis direction. The Z-axis motor 261 raises and lowers the head 25H as necessary when there is a large bend in the mounting substrate P, which is the measurement target. Additionally, in cases where it is not expected that a large amount of warping will occur in the mounting substrate P, the Z-axis motor 261 may be omitted. The R-axis motor 61 is a motor that serves as a driving source for the rotation mechanism 6, and generates a driving force to rotate the head 25H around the imaging optical axis AX.

The camera unit 4 includes a camera body 41 equipped with an imaging device such as a CMOS sensor, an imaging lens 42 that makes a light image of the mounting substrate P incident on the camera unit 4, and the light image is captured by the camera unit 4. It includes a body portion 43 that incorporates an optical system that forms an image on the imaging surface of the device. The light source holder 51 is attached to the body portion 43. The rotation mechanism 6 is also mounted on the body portion 43. When the rotation mechanism 6 rotates the body 43, the entire camera unit 4 rotates around the imaging optical axis AX, and a pair of line light sources 5A and 5B mounted on the light source holder 51 ) also rotates.

6(A) to 6(C) are perspective views showing the rotational state of the head 25H. FIG. 6(A) shows a state where the rotation angle of the head 25H is 0 degrees. In this state, the pair of line light sources 5A and 5B are aligned along the X direction. The line light SL emitted from the line light sources 5A and 5B, respectively, becomes line light extending in the Y direction. FIG. 6(B) shows a state where the rotation angle of the head 25H is 45 degrees. In this case, the line light sources 5A, 5B are lined up on a line inclined at 45 degrees to both the X and Y directions, and the line light SL also extends in a direction inclined at 45 degrees to both the X and Y directions. It becomes a line light. Figure 6(C) shows a state where the rotation angle of the head 25H is 90 degrees. In this state, the pair of line light sources 5A and 5B are lined up along the Y direction, and the line light SL becomes a line light extending in the X direction. In this way, the rotation mechanism 6 rotates the head 25H, so that the irradiation direction of the line light SL can be set to a desired direction.

The Y-axis motor 231, the encoder), Z-axis encoder 262, and R-axis encoder 62 are installed. The Y-axis encoder 232 outputs a position detection signal that detects the Y-direction position of the moving frame 22 (head 25H) at a predetermined resolution. The X-axis encoder 242 outputs a position detection signal that detects the X-direction position of the head 25H at a predetermined resolution. The Z-axis encoder 262 outputs a position detection signal indicating the Z-direction position of the head 25H. The R-axis encoder 62 outputs a position detection signal indicating the rotational position of the head 25H.

The control device 3 is made of a microcomputer, etc., and functionally includes an imaging control unit 31, a scan control unit 32, a measurement processing unit 33, and an implementation data storage unit 34 by executing a predetermined program. Operates to provide. Position detection signals are input to the control device 3 from each of the X-axis, Y-axis, Z-axis, and R-axis encoders 232, 242, 262, and 62 through the server device 30.

The imaging control unit 31 controls the operation of the camera unit 4 and the line light source 5. Specifically, the imaging control unit 31 emits line light (SL) to the line light source 5, issues an imaging command to the camera unit 4 to perform an imaging operation at a predetermined timing, and produces images obtained through the imaging. Image data is received as measurement data. The imaging control unit 31 captures the part C to the camera unit 4 in synchronization with the position detection signal output by the Y-axis encoder 232 and the X-axis encoder 242 in accordance with the movement of the head 25H. By doing so, the component C is scanned. For example, the imaging control unit 31 issues the imaging command whenever the position detection signal reaches a predetermined number of counts. This allows the scanning distance and the size of the scanning direction on the imaging data to be set in an arbitrary proportional relationship. As a result, it becomes possible to acquire height data of the part C at the same pitch no matter what direction the scan direction is.

The scan control unit 32 controls the Y-axis motor 231 and the Move the head (25H) equipped with ) in the desired scan direction. Additionally, the scan control unit 32 operates the Z-axis motor 261 as needed to adjust the height of the head 25H. Additionally, the scan control unit 32 controls the R-axis motor 61 to rotate the head 25H and sets the irradiation direction of the line light SL from the line light source 5 to the desired direction.

The measurement processing unit 33 performs calculation processing to obtain height data of the component C by an optical cutting method based on the image acquired by the camera unit 4 during the scanning. For example, the measurement processing unit 33 detects the reflected light RL1 and RL2 as illustrated in FIG. 2(B) using an image processing method such as edge detection processing. Additionally, the measurement processing unit 33 performs processing to detect the presence or absence of missing portions in the height data. The missing portion corresponds to a location where height data could not be measured, for example, due to the influence of the shadow portion SH shown in Fig. 3(A). It is assumed that a scan (first scan) is performed in a certain scanning direction/irradiation direction of line light SL, and that the missing part is detected in height data obtained based on the image acquired by the scan. In this case, the measurement processing unit 33 causes the imaging control unit 31 and the scan control unit 32 to perform a rescan (second scan) with the scanning direction/irradiation direction of the line light SL in a different direction.

The mounting data storage unit 34 stores mounting data regarding the mounting substrate P. The mounting data includes, for example, the type of component C, XY size, height, number, arrangement position on the board, etc. In some embodiments described later, the implementation data stored in the implementation data storage unit 34 is utilized.

Figure 7 is a perspective view showing the head 25HA according to a modified example. FIG. 4 shows an example in which the head 25H is rotated around the imaging optical axis AX by the rotation mechanism 6 to change the irradiation direction of the line light SL. FIG. 7 illustrates a head 25HA in which the rotation mechanism 6 can be omitted. The head 25HA is composed of a plurality of line light sources 5 arranged at a predetermined pitch on a circumference centered on the imaging optical axis AX of one camera unit 4. Here, an example is shown in which ten line light sources (5a1, 5a2, 5b1, 5b2, 5c1, 5c2, 5d1, 5d2, 5e1, 5e2) are arranged at equal pitches on the circumference. Among these ten line light sources (5a1 to 5e2), one pair is arranged opposite to each other with the imaging optical axis (AX) in between, for example, line light sources (5a1, 5a2) or line light sources (5b1, 5b2). By selecting , the irradiation direction of the line light (SL) can be changed.

[First embodiment of height measurement]

8(A) to 8(D) are schematic diagrams for explaining component height measurement according to the first embodiment. In the first embodiment, the first scan is performed with the irradiation direction of the line light SL as the default orientation, and then the head 25H is rotated to perform the first scan with the irradiation direction of the line light SL in a different orientation. 2 This shows an example of executing a scan. In FIG. 8 and the following drawings, for the sake of simplification, the head 25H is shown as a substantially square camera unit 4, and a pair of cameras arranged with the camera unit 4 in between and shown as an elongated rectangle. It is schematically shown as line light sources (5A, 5B). These also schematically represent the posture of the imaging area of the camera unit 4 and the irradiation direction of the line lights SL1 and SL2 emitted by the line light sources 5A and 5B.

Figure 8(A) shows the first scan. The object of height measurement is a mounting board (P) on which a relatively tall high component (C1) and a relatively short low component (C2) are mounted. The low component (C2) is mounted in an area surrounded by the high component (C1). During the first scan, the scan control unit 32 operates the Y-axis motor 231 and/or the X-axis motor 241 with the rotation position of the head 25H as the default setting position. Thereby, the head 25H is moved in the predetermined scan direction F. In addition, the imaging control unit 31 emits the first line light SL1 or the second line light SL2 from the first line light source 5A or the second line light source 5B, and allows the camera unit 4 to capture an image. Execute the action. The second scan executed later is also the same.

In the first scan, the scan direction F is the X direction (first scan direction), and the opposing direction of the pair of line light sources 5A and 5B is also the X direction. That is, the projection optical axis of the first line light (SL1) or the second line light (SL2) is along the X direction, and the first line light (SL1) or the second line light (SL2) projected on the measurement object extends. The direction is the Y direction orthogonal to the scan direction (F). As is clear from FIG. 8(A), when the scanning direction F is set to the X direction, the area where the low component C2 is sandwiched between two high components C1 lined up in the X direction is scanned. The measurement processing unit 33 performs processing to obtain height data of the high part C1 and the low part C2 by the optical cutting method based on the image acquired by the first scan.

FIG. 8(B) shows the irradiation situation of the first line light SL1 or the second line light SL2 when the first scan is performed in the scan direction F and the line light projection direction of FIG. 8(A). This is a drawing that represents. The first line light SL1 emitted from the first line light source 5A is blocked by the high component C1 on the left side of the figure and cannot illuminate the low component C2. Additionally, the second line light SL2 emitted from the second line light source 5B is also blocked by the high component C1 on the right side of the figure and cannot illuminate the low component C2.

When the high component C1 exists only in one of the low components C2, either the first line light SL1 or the second line light SL2 is used as shown in FIG. 3(B). You can irradiate the part (C2). However, if the high component C1 is present on both sides of the low component C2, there may be cases where it becomes impossible to irradiate both the first line light SL1 and the second line light SL2 to the low component C2. You can. In this case, since the reflected light from the low component C2 does not enter the camera unit 4, the measurement processing unit 33 cannot obtain height data for the mounting area of the low component C2. In this case, the measurement processing unit 33 determines that “there is” a height data missing portion in the height measurement based on the first scan.

When a height data missing portion is detected, the measurement processing unit 33 executes a second scan with at least the irradiation directions of the line lights SL1 and SL2 in different directions. FIG. 8(C) is a diagram showing a first example of the second scan. In this first example, the scan direction F is maintained in the same X direction as in the first scan, while the head 25H is rotated by only about 45 degrees. The low component C2 is inserted into the high component C1 when viewed from the

By rotating the head 25H, the imaging area of the camera unit 4 is also rotated by approximately 45 degrees around the imaging optical axis AX. Additionally, the irradiation direction (projection optical axis) of the line lights SL1 and SL2 also rotates around the imaging optical axis AX. That is, the relationship between the irradiation direction of the line lights SL1 and SL2 and the posture of the imaging area remains the same as in the first scan. The direction in which the line lights (SL1, SL2) extend is inclined at an angle of approximately 45 degrees with respect to the X direction. By performing the second scan in this irradiation direction, both the first line light SL1 and the second line light SL2 can be irradiated to the low component C2. Therefore, the measurement processing unit 33 can obtain the height data of the low part C2, which was the missing part of the height data, based on the image acquired by the second scan. Additionally, since the relationship between the posture of the imaging area and the irradiation direction of the line lights SL1 and SL2 remains the same in the first scan and the second scan, height data can be derived efficiently.

Figure 8(D) is a diagram showing a second example of the second scan. This second example shows an example in which the second scan is performed by setting the scan direction F to a direction different from the first scan. The scan direction (F) of the second scan is a direction (second scan direction) inclined by about 45 degrees with respect to the X direction, which is the scan direction (F). The head 25H is rotated similarly to the first example, and the imaging area of the camera unit 4 and the irradiation direction of the line lights SL1 and SL2 are also rotated by about 45 degrees with respect to the settings of the first scan. In the second example, in both the first scan and the second scan, a relationship in which the scan direction F and the direction in which the line lights SL1 and SL2 extend are orthogonal is maintained. In this second example, either the first line light SL1 or the second line light SL2 is irradiated to the low part C2 in the second scan, and the low part C2, which was a missing part of the height data, is scanned. Height data can be obtained.

9(A) to 9(D) are schematic diagrams for explaining another example in which missing portions of height data occur and an example of component height measurement in that case. As shown in FIG. 9(A), on an actual mounting board P, components C may be mounted with a narrow pitch W between components. If a scan is performed on such a mounting board P in which the arrangement direction of the components C matches the scan direction F, height data between the components C may not be acquired.

Referring to FIG. 9(B), when two components C are arranged on the mounting board P with a narrow inter-component pitch W along the scan direction F, the first line light SL1 or the first line light SL1 A region occurs in which neither of the two line lights (SL2) reaches the substrate surface (PS). When the line lights SL1 and SL2 are irradiated toward the substrate surface PS at the intersection angle θ (FIG. 2), if the height of the component C is H,

W=H/tanθ

With the pitch W between components below, the line lights SL1 and SL2 are blocked by the component C. In this case, missing portions of height data occur in the area of the pitch (W) between parts.

An example of height measurement of the mounting board P including the arrangement of the components C as described above is shown in FIGS. 9(C) and 9(D). Here, a mounting board P on which a plurality of components C are arranged in a matrix in the XY direction at a narrow pitch is exemplified. In the first scan shown in FIG. 9(C), the scan direction F is set to the X direction (first scan direction). The opposing direction of the pair of line light sources 5A and 5B is also the X direction. Meanwhile, the direction in which the first line light SL1 or the second line light SL2 projected on the substrate surface PS extends is the Y direction. In this first scan, there is a possibility that the pitch Wx area of the parts C lined up in the Height data can be acquired.

Figure 9(D) shows the second scan. The scan direction (F) of the second scan is set to the Y direction rotated by 90 degrees from the X direction. That is, the head 25H is rotated 90 degrees. As a result, for the first scan, the imaging area of the camera unit 4 is rotated about 90 degrees around the imaging optical axis AX, and the irradiation direction of the line lights SL1 and SL2 is also aligned with the imaging optical axis AX. It is rotated 90 degrees around the circumference. In this second scan, there is a possibility that the area of the pitch Wy of the parts C lined up in the Y direction becomes a missing part of the height data. However, height data can be acquired for the area of the pitch Wx of the parts C lined up in the X direction, which became the height data missing portion in the first scan. Therefore, by combining the measurement results of the first scan and the second scan, the missing portion of height data can be eliminated.

[Second Embodiment]

In the second embodiment, in order to simplify movement control of the head 25H, an example is shown in which the scan direction F is limited to either the X direction or the Y direction. That is, an example is shown in which the control device 3 selects and operates either the Y-axis movement mechanism 23 or the X-axis movement mechanism 24 when performing the first scan and the second scan. In the above selection, scannable width, scan distance, etc. are referred to.

In height measurement using a mounting board (P) or the like as a measurement target, the head 25H must be moved so that line light (SL) is irradiated to the entire area of the measurement target. At this time, if the Y-axis movement mechanism 23 and the X-axis movement mechanism 24 are operated simultaneously, the scan direction F can be set to any direction. For example, the middle direction between the X and Y directions as illustrated in FIG. 8(D) can be set as the scan direction (F). However, in this case, the scan control unit 32 must synchronously control the Y-axis motor 231 and the X-axis motor 241, making drive control complicated. In order to simplify drive control, it is desirable to control to operate only one of the Y-axis motor 231 or the X-axis motor 241 during scanning. In addition, when selecting either the

As explained based on FIG. 3(C), in order to avoid the influence of the shadow portion SH of the component C, it is necessary to scan so that both of the two line lights SL1 and SL2 pass over the measurement object. there is. However, depending on the rotation angle of the head 25H, a wide difference occurs in the scannable width in the X direction and Y direction. This point will be explained based on FIGS. 10(A) to 10(D). In Fig. 10, an imaging area 4A of the camera unit 4 and line lights SL1 and SL2 projected within this imaging area 4A are shown.

FIG. 10(A) shows a state where the rotation angle of the head 25H is 0 degrees. In a state of 0 degrees, the line lights SL1 and SL2 extend along the Y direction. For this reason, in the X-direction scan in which the X-direction is selected as the scan direction (F), the scannable width (X) becomes the maximum width (max). On the other hand, in Y-direction scan in which the Y-direction is selected as the scan direction (F), the scannable width (Y) becomes zero and measurement is not possible.

Fig. 10(B) shows a state where the rotation angle of the head 25H is 30 degrees. In the 30-degree state, the area where both the two line lights (SL1 and SL2) can be irradiated in X-direction scanning is narrower than in the 0-degree state. For this reason, the scannable width (X) becomes X=x1, which is smaller than the maximum width (max). On the other hand, in Y-direction scanning, the area that can be irradiated by both line lights SL1 and SL2 is not zero, and the scannable width Y = y1. However, y1<x1. Fig. 10(C) shows a state where the rotation angle of the head 25H is 60 degrees. In a state of 60 degrees, the extension direction of the line lights SL1 and SL2 approaches the Y direction, so the scannable width (Y) in the Y direction increases, while the scannable width (X) in the X direction decreases. That is, the relationship is scannable width (X) = x2, scannable width (Y) = y2, and y2>x2.

FIG. 10(D) shows a state where the rotation angle of the head 25H is 90 degrees. In the 90 degree state, the line lights SL1 and SL2 extend along the X direction. For this reason, the scannable width (Y) of the Y-direction scan becomes the maximum width (max), while the scannable width (X) of the X-direction scan becomes zero, making measurement impossible. As described above, it is necessary to select an appropriate one of the X direction or the Y direction as the scan direction F according to the rotation angle of the head 25H.

11(A) to 11(C) are diagrams explaining a method for determining the scan direction (F). The relationship between the rotation angle of the head 25H and the measurable width in X-direction scan or Y-direction scan can be obtained as follows. As shown in Fig. 10(A), the rotation angle of the head 25H is α, the measurable width when α = 0 degrees is L, and the distance between the two line lights SL1 and SL2 is D.

As shown in Fig. 11(B), when the rotation angle of the head 25H = α, the measurable width Lx when X-direction scanning is performed is expressed by the following equation. Additionally, “abs” represents the absolute value and “·” represents the multiplication.

Lx=abs(L·cosα)-abs(D·sinα)

On the other hand, as shown in Fig. 11(C), when the rotation angle of the head 25H = α, the measurable width Ly when Y-direction scanning is performed is expressed by the following equation.

Ly=abs(L·sinα)-abs(D·cosα)

The larger the value of the measurable width (Lx, Ly) above, the larger the measurement width in one scan. Therefore, by comparing the values of the X-direction measurable width (Lx) and the Y-direction measurable width (Ly) and selecting the larger one as the scan direction (F), efficient height measurement can be performed. Additionally, when the rotation angle = 45 degrees, the values of the measurable widths (Lx, Ly) are the same. In this case, the shorter the scan distance, the shorter the time required for scanning, so it is preferable to select the shorter scan distance among X-direction scanning or Y-direction scanning.

Fig. 12 is a flowchart showing scan direction determination processing in component height measurement according to the second embodiment. The scan control unit 32 of the control device 3 rotates the head 25H around the imaging optical axis AX at a desired rotation angle α (step S1). This rotation angle α is, for example, a rotation angle at which the line light SL can be irradiated to the low component C2 surrounded by the high component C1 as illustrated in FIG. 8(C). Hereinafter, processing to select either X-direction scan or Y-direction scan is performed.

Next, the scan control unit 32 calculates the X-direction measurable width Lx and the Y-direction measurable width Ly) using the above calculation formula based on the rotation angle α set in step S1 (step S2). Subsequently, the scan control unit 32 compares the values of the measurable widths (Lx, Ly). First, it is determined whether the inequality of Lx>Ly is satisfied (step S3). If Lx>Ly is satisfied (YES in step S3), the scan control unit 32 selects an X-direction scan with a wide measurement width (step S4). On the other hand, if Lx>Ly is not satisfied (NO in step S3), it is determined whether the inequality of Lx<Ly is satisfied (step S5). If Lx<Ly is satisfied (YES in step S5), the scan control unit 32 selects the Y direction scan (step S6).

In this case, if Lx<Ly is not satisfied (NO in step S5), it is assumed that Lx=Ly. In this case, the scan control unit 32 compares the scan distance when X-direction scanning is adopted and the scan distance when Y-direction scanning is adopted (step S7). For example, in the example of Fig. 8(B), in the first scan, the area sandwiched between the two high components C1 becomes a missing part of the height data. When re-measuring this missing portion area with the second scan, it is determined which of the X-direction scan or Y-direction scan is adopted has a shorter scan distance. For example, if the missing area is a rectangular area long in the Therefore, when the X-direction scan distance is longer than the Y-direction scan distance (YES in step S7), the scan control unit 32 selects the Y-direction scan (step S8). Conversely, if the Y-direction scan distance is longer than the X-direction scan distance (NO in step S7), the scan control unit 32 selects the X-direction scan (step S9).

[Third Embodiment]

The third embodiment shows an example of determining the scanning direction F using the mounting data of the component C. Which components (C) are mounted on the mounting board (P) and in what layout are predetermined by mounting data. The mounting data is information about the shape of the component C and the mounting position on the board, and is stored in the mounting data storage unit 34. By utilizing this mounting data, it is possible to detect the irradiation direction or scanning direction (F) of the line light (SL) in which no height data missing portions occur or with the fewest height data missing portions. In the third embodiment, an example is shown in which the measurement processing unit 33 reads the mounting data from the mounting data storage section 34 and determines whether or not a missing portion of the height data has occurred.

13(A) to 13(E) are schematic diagrams for explaining component height measurement according to the third embodiment. In the default state as shown in Fig. 13(A), the posture and scanning direction F of the head 25H including the camera unit 4 and the line light sources 5A and 5B are assumed to be determined. The measurement processing unit 33 acquires mounting data for the mounting substrate P that is the measurement target from the mounting data storage section 34 before executing the scan. The simplest example is a case in which missing portions of height data do not occur even if a scan is executed in the default state. In this case, height measurement is completed simply by executing the first scan in the default state. The second scan becomes useless.

Figures 13(B) and 13(C) show examples of acquisition of implementation data. FIG. 13(B) corresponds to an example of the arrangement of the parts C1 and C2 shown in FIG. 8(A), and FIG. 13(C) corresponds to an example of the matrix arrangement of the parts C shown in FIG. 9(C). By acquiring the mounting data, it is possible to create a three-dimensional model of the mounting board P after the components are mounted. The measurement processing unit 33 uses this three-dimensional model to determine the scanning mode. As described above, when scanning is performed in the default state in both examples of Figs. 13(B) and 13(C), missing portions of height data occur.

In this case, the measurement processing unit 33 performs a simulation to variously change the irradiation direction or scanning direction F of the line light SL to calculate the optimal scanning mode. Figures 13(D) and (E) show examples of determination of the scan mode when the mounting data of Figures 13(B) and (C) are acquired, respectively. FIG. 13(D) corresponds to the scan mode in FIG. 8(C), and FIG. 13(E) corresponds to the scan mode in FIG. 9(D).

For example, in the case where the mounting data in Fig. 13(B) was acquired, it was determined that no missing portions of the height data occurred in the scanning mode with the rotation angle of the head 25H as shown in Fig. 13(D). Do it as done. In this case, only the first scan is performed in the scanning mode of Fig. 13(D), and the height measurement of the mounting substrate P is completed. In the scan mode of FIG. 13(D), if missing height data occurs in other parts, for example, the first scan is performed in the default scan mode of FIG. 13(A), and the second scan is performed in the default scan mode of FIG. 13(D). ) to supplement the height data by executing in the scan mode. Additionally, when the mounting data in FIG. 13(C) is acquired, in the scan mode in FIG. 13(E), missing portions of height data occur between component pitches in the Y direction. Accordingly, it is decided to execute the first scan in the default scan mode in FIG. 13(A) and to execute the second scan in the scan mode in FIG. 13(E).

[Fourth Embodiment]

In the fourth embodiment, when a missing part of height data is detected in the first scan, it is determined whether the cause of the missing part is due to the scan direction, and if the missing part is due to the scan direction, a second scan is performed. Shows an example of what to do. The missing height data does not occur solely due to the shadow portion (SH) of the component (C). For example, if there are openings or notches in the mounting substrate P, reflected light from the substrate surface PS cannot be detected for these portions, resulting in height data missing portions. Even if a second scan is performed on such missing portions, height data cannot be obtained and it becomes a waste of time. Therefore, even when a height data missing portion area occurs, it is desirable to perform a second scan on the missing portion area after determining whether the missing portion failed the height measurement due to the scan direction.

An example of determination of whether to perform the second scan for the height data missing portion is shown. Figures 14(A) and (B) are schematic diagrams showing one aspect of the above determination. Here, when the height data missing part is adjacent to the data area where the height data is acquired in the scanning direction (F), the missing part is determined to be a missing part due to the scanning direction.

FIG. 14(A) shows a case where the mounting board P1, which is the measurement target, has a component layout in which a low component C2 is arranged between two high components C1. As shown in (A-1) of FIG. 14(A), it is assumed that the first scan for measuring the height of the mounting substrate P1 is performed using the direction in which the two high components C1 are lined up as the scanning direction. (A-2) in FIG. 14(A) shows an image IM1 of height data obtained based on the first scan. The two high components C1 are expressed as data-containing areas where height data higher than the height of the substrate surface PS (loading surface) is obtained. On the other hand, two shadow parts SH1 and SH2 whose heights are not detected are expressed in the image IM1. In one shadow portion SH1, an isolated area CA is shown that extends thinly and long in a direction perpendicular to the scanning direction.

One shadow portion SH1 is a shadow portion adjacent to the two high components C1, which are data containing areas, in the scanning direction. In this case, it can be said that there is a high possibility of measurement failure in the shadow portion SH1 because the line light SL is blocked by the high component C1. In reality, height data of the low component C2 sandwiched between the high component C1 is not obtained. Additionally, the isolated area CA is an error area detected as a data containing area due to diffuse reflection of the line light SL. Normally, parts of this shape do not exist, so they are deleted as noise. On the other hand, the other shadow portion SH2 is not a shadow portion adjacent to the scan direction for either high component C1.

(A-3) in FIG. 14(A) shows an example of determination of the execution area of the second scan when the situation (A-2) is obtained. The shadow area SH1 adjacent in the scanning direction to the data area corresponding to the two high components C1 is determined as the re-scan area RS1 to be the target area for the second scan. Meanwhile, the shadow portion SH2 that is not adjacent to the data containing area in the scan direction is not treated as the re-scan area RS1. In the second scan performed later, the height of the re-scan area RS1 is measured by, for example, changing the irradiation direction of the line light SL. According to this embodiment, it is possible to speed up height measurement by eliminating the need for a useless second scan to be performed.

FIG. 14(B) shows a case where the mounting substrate P2 to be measured has a notch portion PD2. As shown in (B-1) of FIG. 14(B), the mounting board P2 is adjacent to the downstream side in the scanning direction of the mounted component C, and has a notch portion ( I have PD2). (B-2) in FIG. 14(B) shows an image IM2 of height data obtained based on the first scan. The mounting area of the component (C) is expressed as a data area with height data higher than the substrate surface (PS). Meanwhile, the area of the notch portion PD2 becomes a shadow portion SH3 without height data.

(B-3) in FIG. 14(B) shows an example of determination of the execution area of the second scan when the situation (B-2) is obtained. In this case, although the shadow portion SH3 is adjacent to the data containing area corresponding to the component C, the entire area is not used as the target area for the second scan. Among the shadow areas SH3, only the area adjacent to the scan direction, that is, the area located downstream in the scan direction, with respect to the area that clearly contains data of the part C, is determined as the re-scan area RS2. Since this rescan area RS2 is also an area corresponding to the notch PD2, as a result, height data is not measured even in the second scan. However, since the execution area of the second scan is limited, it can contribute to speeding up height measurement.

15(A) and 15(B) are schematic diagrams showing other precedents for whether or not a second scan is performed for the height data missing portion. Here, in the case where the height data missing part adjacent to the data containing area in the scanning direction (F) is a missing part of less than a predetermined number of pixels in the image obtained by the first scan, an example is given in which it is determined that the missing part is due to the scanning direction. indicates. In the example of FIG. 14, even if it is the notch PD2, it is determined as the object of the second scan as long as it is adjacent to the data containing area in the scanning direction. This judgment example shows an example of suppressing this problem.

FIG. 15(A), similar to FIG. 14(A), shows a case where the mounting board P1 to be measured has a component layout in which a low component C2 is disposed between two high components C1. It is assumed that the first scan for measuring the height of the mounting board P1 is performed using the direction in which the two high components C1 are lined up as the scan direction. As shown in (A-2) of FIG. 15(A), the area corresponding to the two high components C1 becomes an area with data, and between them is a shadow area SH1 whose height is not detected and an isolated area ( CA) is shown. In determining whether execution of the second scan is necessary or unnecessary, the isolated area CA is ignored as noise, and the width d1 in the scan direction of the shadow area SH1, which is a missing part of the height data, is evaluated by the number of pixels in the image. Here, since the width d1 of the shadow portion SH1 is a missing portion less than a predetermined number of pixels n, it is determined that the shadow portion SH1 is treated as an object of the second scan.

FIG. 15(B), like FIG. 14(B), shows a case where the mounting substrate P2 to be measured has a notch portion PD2. The mounting substrate P2 has a notch portion PD2 adjacent to the downstream side of the component C in the scan direction. As shown in (B-2) of Fig. 15(B), the area corresponding to the part C becomes an area with data, and the area of the notch portion PD2 becomes a shadow portion SH3 without height data. Similarly to the above, the width d2 of the shadow portion SH3 in the scanning direction is evaluated based on the number of pixels in the image. Here, since the width d2 of the shadow portion SH3 is a missing portion greater than or equal to a predetermined number of pixels n, it is determined that the shadow portion SH3 is not treated as an object of the second scan.

The predetermined number of pixels (n) can be set to any value greater than 0. For example, when a missing portion of height data is detected and the entire portion is to be re-scanned, n = 0 can be set. Alternatively, the number of pixels (n) may be set dynamically from the relationship between the average height around the height data missing portion and the irradiation angle of the line light (SL). Additionally, the number of pixels (n) can be set based on the number of pixels for which height data is supplemented by image processing. For example, if the number of pixels without height data is 3 or less, n = 4 is set to derive the height data of the pixels without data through supplementary processing. In this way, the standard for determining that the height data is missing, which becomes the trigger for executing the second scan, can be arbitrarily set by the number of pixels (n).

Fig. 16 is a flowchart showing scan area determination processing in component height measurement according to the fourth embodiment. The scan control unit 32 of the control device 3 executes a first scan defined by default settings and performs a height measurement on the mounting substrate P as a measurement target (step S11). Subsequently, the measurement processing unit 33 obtains height data and height data missing portions based on the image obtained in the first scan (step S12).

Next, the measurement processing unit 33 determines whether there is an isolated area CA in which the height data is unnaturally isolated as illustrated in FIG. 14(A) in the height data missing portion (step S13). When the isolated area CA is detected (YES in step S13), since the area is noise, the measurement processing unit 33 performs processing to delete the isolated area CA (step S14). When the isolated area CA is not detected (NO in step S13), the measurement processing unit 33 determines whether there is a data area adjacent to the height data missing area in which height data higher than the substrate surface PS is detected. Determine whether or not (step S15).

If the data-containing area exists (YES in step S15), the measurement processing unit 33 determines whether the height data missing portion is a missing portion corresponding to the shadow in the scanning direction (step S16). That is, the measurement processing unit 33 determines whether the height data missing part detected in step S2 is a missing part adjacent to the data containing area in the scan direction. In the case of a missing part adjacent to the scan direction (YES in step S16), the measurement processing unit 33 determines whether the height data missing part is a missing part with a width of more than a predetermined number (n) of pixels in the scan direction on the image. Do it (step S17).

When it is determined that the missing portion has a width equal to or greater than the number of pixels (n) (YES in step S17), the measurement processing unit 33 determines that the height data missing portion is a missing portion that requires re-scanning. In this case, it is determined whether all specified height measurements have been completed (step S18). If the height measurement is incomplete (NO in step S18), the scan control unit 32 changes the rotation angle of the head 25H and changes the scan direction F as necessary (step S20), returns to step S11, and restarts. The second scan as a scan is executed. For example, a rescan is performed by changing the rotation angle by 15 degrees.

When all height measurements have been completed (YES in step S18), the measurement processing unit 33 stores the height measurement data for the mounting substrate P as the measurement target in the memory area of the control device 3, and stores the data as Update (step S19). On the other hand, if the data-containing area does not exist in step S15 (NO in step S15), if it is not a missing area adjacent to the scan direction in step S16 (NO in step S16), or if the area has a width of more than the number of pixels (n) in step S17. (YES in step S17), the measurement processing unit 33 determines that re-scanning is not necessary (step S21) and ends the process.

[Fifth Embodiment]

The fifth embodiment shows an example of detecting a desirable scan mode in advance using a model substrate. Schematically, the scan control unit 32 executes a plurality of scans with the irradiation directions of the line lights SL1 and SL2 in different orientations on the model substrate, and selects a scan suitable for use as the first scan among the plurality of scans. Select Scan. Then, in the subsequent height measurement of the mounting board P, which is the same as the model board, the height is measured in the selected scan mode.

17(A) to 17(C) are schematic diagrams for explaining component height measurement according to the fifth embodiment. In this embodiment, a model substrate PM as shown in Fig. 17(A) is prepared. A model board (PM) is a good quality board in which components (C) are mounted on a board in a predetermined arrangement according to the board design for a certain mounting board product. Here, like the example product in FIG. 8(A), it has a layout in which one low component (C2) is surrounded by four high components (C1).

Before measuring the height of the mounted substrate product, the control device 3 performs a height measurement operation on the model substrate PM. In this height measurement, the scan control unit 32 sequentially rotates the head 25H, for example, and performs a plurality of height measurements with the irradiation directions of the line lights SL1 and SL2 in different directions. Figure 17(A) shows an example in which the rotation angle of the head 25H is sequentially changed to 0 degrees, 45 degrees, and 90 degrees, and the model substrate PM is scanned in the scan directions F1, F2, and F3, respectively. . In reality, it is preferable to scan the model substrate PM while changing the rotation angle of the head 25H at a small pitch of about 15 degrees.

Based on the images acquired in each scan, the measurement processing unit 33 obtains height data of the model substrate PM. At this time, the measurement processing unit 33 identifies missing portions of height data in each scan and evaluates how accurately the height measurement was performed based on the mounting data. In Fig. 17(A), when the rotation angle of the head 25H = 0 degrees and 90 degrees, the height of the low part C2 cannot be measured, so it cannot be evaluated as an optimal scanning mode. On the other hand, when the rotation angle = 45 degrees, height measurement including the low part (C2) is possible. Therefore, when the measurement processing unit 33 sets the mounting board P on which the components C1 and C2 are mounted in the same arrangement as the model board PM with the rotation angle of the head 25H = 45 degrees as the object of height measurement. , is adopted as a scanning mode.

Figures 17(B) and 17(C) show a scan mode for the mounting board P, which is the same as the model board PM, to be performed later. These are the same as the scanning aspects shown in Figs. 8(C) and 8(D) of the first embodiment. FIG. 17(B) shows an example in which scanning is performed with the rotation angle of the head 25H = 45 degrees while maintaining the scan direction F1 with the rotation angle = 0 degrees. Figure 17(C) shows an example in which the rotation angle of the head 25H is set to 45 degrees and the scan direction F2 is set according to this rotation angle.

According to the fifth embodiment, a plurality of scans are performed in advance using the model substrate PM, and it becomes possible to detect the optimal scan in which missing height data parts are least likely to occur. And, for the mounting substrate P that is the same as the model substrate PM, height measurement without waste can be performed by applying the above-mentioned optimal scan mode to at least the first scan.

In the fifth embodiment, when there is mounting data that can calculate the height, volume, and area of the component C, the height, volume, and area obtained from the measured values in each scan are the closest to the mounting data. You can select the nearest scan mode. Figure 18 shows an example of evaluating the scan direction using the volume ratio, which is the ratio of the volume obtained from the mounting data for the low component (C2) and the high component (C1) and the volume obtained by actual measurement in each scan. . The closer the volume ratio is to 100%, the more accurate the measurement is.

FIG. 18(A) shows the volume ratio of the low part C2 and the high part C1 in the case where the scanning direction and the rotation angle of the head 25H = 0 degrees. As described, in the case of 0 degrees, the low part (C2) becomes a shadow of the high part (C1), so accurate height measurement cannot be performed. For this reason, the volume ratio for low components (C2) is a low value of 1%. On the other hand, since there is no problem in measurement for large components (C1), a high value of 95% for the volume ratio is obtained.

Figure 18(B) shows the volume ratio in the case where the scan direction and rotation angle of the head 25H = 45 degrees. In the case of 45 degrees, line light (SL1, SL2) can be irradiated even to the low part (C2). For this reason, the volume ratio for the low component (C2) is obtained as high as 99%. Even for high-volume components (C1), a high value of 97% is obtained for the volume ratio. Figure 18(C) shows the volume ratio in the case of rotation angle = 90 degrees. Even in this case, the low part (C2) becomes a shadow of the high part (C1), so accurate height measurement cannot be performed. Accordingly, the volume ratio of the high component (C1) is 94%, but the volume ratio of the low component (C2) is a low value of 2%.

According to the above results, when the rotation angle is 0 degrees and 90 degrees, accurate height measurement cannot be performed at least in the mounting area of the low component C2 and the high component C1. Therefore, a scan with rotation angle = 45 degrees is selected. In an actual mounting substrate P, a plurality of mounting areas exist, and a preferable scan direction exists for each of these mounting areas. It is desirable to set the optimal scan mode when looking at the entire mounting substrate P, such as by arranging mounting areas or components with the same preferred scan direction.

Fig. 19 is a flowchart showing scan direction determination processing when mounting data can be used in component height measurement according to the fifth embodiment. The scan control unit 32 of the control device 3 executes a scan specified by default settings on the model board PM and measures the height of the mounted component C (step S31). Subsequently, the measurement processing unit 33 obtains height data for each component C of the model board PM. In addition, the measurement processing unit 33 reads the mounting data from the mounting data storage unit 34 and calculates the volume ratio from the volume based on the height data of the actually measured component C and the volume of the component C1 derived from the actually measured data. Calculate (step S32).

Subsequently, it is confirmed whether the measurement of the height of the model substrate PM in the pre-specified rotation angle of the head 25H and the scan direction has been completed (step S33). If all height measurements are incomplete (NO in step S33), the scan control unit 32 changes the rotation angle or scan direction of the head 25H (step S35) and executes a new scan (step S31). On the other hand, when all height measurements are completed (YES in step S33), the measurement processing unit 33 specifies the scan direction in which a result closest to the mounting data was obtained among all scans performed for each component C and stores this (step S34).

The above is an example of a method for determining the scan direction when mounting data is available. If mounting data is not available, the optimal scan direction can be selected from the relationship between the area of the missing part in the height data and the scan direction. 20(A) to 20(C) are diagrams showing the relationship between the scan direction and the shadow portions SH1, SH21, SH22, and SH3, which are missing height data portions, in measuring the height of the component C. Figures 20(A), (B), and (C) show measurement results for the scan direction and rotation angle of the head 25H = 0 degrees, 45 degrees, and 90 degrees, respectively.

Based on the images acquired by each scan in Figs. 20(A) to 20(C), the data containing area, which is the area of the part C, is specified. Next, for this data-containing area, the area of the missing portion of height data adjacent to the scanning direction is calculated. As shown in FIG. 20(A), when the rotation angle is 0 degrees, the long side of the rectangular component C is perpendicular to the scanning direction, so the shadow portion SH1 of a relatively large area, that is, the missing portion, is expressed. there is. In contrast, when the rotation angle in Fig. 20(B) is 45 degrees, shadow portions SH21 and SH22 of relatively small areas are expressed at the corner portion on the downstream side of the scanning direction of the component C1. At a rotation angle of 90 degrees in Fig. 20(C), a shadow portion SH3 with an area larger than the sum of SH21 and SH22 is expressed on the short side of the component C.

Among these scans in Figs. 20(A) to 20(C), the scan in which the area of the missing portion is smallest is selected as the first scan. In this example, the shadow portions (SH21, SH22) detected by scanning with the rotation angle = 45 degrees in Fig. 20(B) have the smallest area compared to the others. In other words, a rotation angle of 45 degrees is the scan in which missing portions of height data are least likely to occur. Therefore, a scan with the rotation angle of the head 25H = 45 degrees is selected as at least the first scan.

Fig. 21 is a flowchart showing scan direction determination processing when mounting data cannot be used in component height measurement according to the fifth embodiment. The scan control unit 32 of the control device 3 executes a scan specified by default settings on the model board PM and measures the height of the mounted component C (step S41). Subsequently, the measurement processing unit 33 executes processing to determine the height data missing portion for the model substrate PM (step S42). The processing in step S42 is the same as the processing in steps S12 to S17 in FIG. 16 described previously. An explanation is given here.

After that, the measurement processing unit 33 performs processing to determine the area of the height data missing portion generated by the scan (step S43). Subsequently, it is confirmed whether the height measurement of the model substrate PM in the pre-specified rotation angle of the head 25H and the scan direction has been completed (step S44). If all height measurements are incomplete (NO in step S44), the scan control unit 32 changes the rotation angle or scan direction of the head 25H (step S46) and executes a new scan (step S41). On the other hand, when all height measurements are completed (YES in step S44), the measurement processing unit 33 selects the scan with the minimum area of the height data missing portion (step S45). The scan mode selected here is used to measure the height of the mounting board P, which is the same as the model board PM, to be performed later.

[Sixth Embodiment]

The sixth embodiment shows an example of acquiring fixed height data of a specific part. For example, for parts of high importance, it may be requested to obtain the shape at a fixed resolution. In this case, in addition to executing a first scan for the part, at least a second scan is executed considering that there is a missing portion of height data in the first scan. That is, regardless of the presence or absence of height data missing portions, the component is scanned multiple times. Then, the height data obtained from at least the images obtained by the first scan and the second scan are synthesized to obtain the height data of the part.

22(A) to 22(D) are schematic diagrams for explaining component height measurement according to the sixth embodiment. The measurement target is a specific component (CP) mounted on the mounting board (P). Specific components (CPs) are critical components, for example, large-scale integrated circuit components. As shown in Fig. 22(A), a plurality of scans are performed for a specific component CP by varying the rotation angle of the head 25H, that is, the irradiation direction of the line lights SL1 and SL2. FIG. 22(A) shows an example in which a first scan using the X direction as the scan direction F1 and a second scan using the Y direction as the scan direction F2 are performed for a specific component CP.

Figure 22(B) shows the height data of the specific component CP obtained based on the image acquired in the first scan, and the shadow portion SHx, which is a missing portion of the height data. Although a shadow portion (SHx) is shown on the FIG. 22(C) shows the height data of the specific component CP and the shadow portion SHy based on the second scan. A shadow portion (SHy) is shown on the Y side (YS) of the specific component (CP), but a shadow portion does not exist on the X side edge (XS). In the height measurement using the first scan, the height data of the X side (XS) is not confirmed. In addition, in the height measurement by the second scan, the height data of the Y side (YS) is not confirmed. However, as shown in FIG. 22(D), if the height data obtained from the first scan and the second scan are combined, the uncertain portion due to the shadow portions SHx and SHy can be eliminated. Therefore, height data of a specific component (CP) can be obtained at a fixed rate.

Fig. 23 is a flowchart showing the high-detail part height data creation process according to the sixth embodiment. The scan control unit 32 of the control device 3 executes a scan specified with default settings for the specific component CP and performs height measurement of the specific component CP (step S51). Based on this height measurement, the measurement processing unit 33 obtains the height data and shadow portions SHx and SHy of the specific component CP (step S52).

Subsequently, it is confirmed whether the height measurement required for data synthesis as illustrated in FIGS. 22(B) to 22(D) has been completed (step S53). If all height measurements are incomplete (NO in step S53), the scan control unit 32 changes the rotation angle or scan direction of the head 25H (step S54) and executes a new scan (step S51). On the other hand, when all height measurements are completed (YES in step S53), the measurement processing unit 33 performs synthesis processing of the height data (step S55).

In step S55, for example, as illustrated in FIGS. 22(C) and 22(D), the shadow portions SHx and SHy are present only on either the If it does not exist, synthesis processing is performed to adopt the height data of the other side as is. That is, the height data of the specific part CP is created by using the height data of the Y side YS obtained in the first scan as is and the height data of the X side side XS obtained in the second scan. In relation to this, in a plurality of scans, shadow portions (SHx, SHy) may appear on either the X-side (XS) or the Y-side (YS). In this case, height data can be created by employing the average, median, maximum value, or minimum value of the height data obtained from multiple scans.

[Other modified embodiments]

Although various embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and, for example, the following modified embodiments can be adopted.

(1) In the above embodiment, an example is shown in which the camera unit 4 and the line light sources 5A and 5B are rotated integrally by rotating the head 25H around the imaging optical axis AX. Instead of this, the irradiation direction of the line light SL may be changed by rotating only the line light sources 5A and 5B. In the above example, the camera unit 4 and the camera unit 4 are positioned so that the relationship between the posture of the imaging area 4A of the camera unit 4 and the irradiation direction of the line lights SL1 and SL2 is maintained, as shown in Fig. 24(A). The line light sources 5A and 5B are all rotated. In contrast, the modified example shown in Fig. 24(B) shows an example in which the camera unit 4 is not rotated and only the line light sources 5A and 5B are rotated. In this case, the relationship between the posture of the imaging area 4A and the irradiation direction of the line lights SL1 and SL2 changes from the case in Fig. 24(A). Additionally, the scan direction can be set to be perpendicular to the extension direction of the line lights SL1 and SL2.

(2) In general, the entire number of pixels of the image data captured by the camera unit 4 is transmitted to the control device 3. Instead of this, in order to speed up processing, only part of the image data may be transmitted. Fig. 25 is a schematic diagram showing an example of limiting image data to be used. In the light cutting method, what is needed from the image data is the surrounding area of the line light (SL1, SL2). For example, assume that line lights SL1 and SL2 are irradiated as shown in Fig. 24(B). In this case, the image data of the entire imaging area 4A provided by the CMOS sensor of the camera body 41, etc. is not transmitted, but is present in the imaging area ROI of the line lights SL1 and SL2, as shown in FIG. 25. Only the data of the image being cut out and transmitted. This makes it possible to speed up data processing.

[Invention included in the above embodiment]

A workpiece height measuring device according to one aspect of the present invention has an imaging optical axis in a vertical direction, an imaging unit that captures an image of a workpiece, and a projection optical axis having a predetermined intersection angle with respect to the imaging optical axis, and has a plurality of projection optical axes with respect to the workpiece. A line light projection unit capable of irradiating line light from an orientation, a scan driver for moving the image pickup unit and the line light projection unit to scan a workpiece, and controlling the scan driver to execute the scan, a measuring unit that obtains height data of the workpiece by an optical cutting method based on an image acquired by scanning; the measuring unit irradiates the line light to the workpiece from a predetermined irradiation direction to perform a first scan; In the height data obtained based on the image acquired in the first scan, the presence or absence of a missing part of the height data of the work is determined, and when the missing part is detected, the irradiation direction of the line light is set to an orientation different from that of the first scan. Run the second scan.

According to this workpiece height measuring device, when a missing part is detected in the height data obtained in the first scan, a second scan is performed with the line light irradiation direction set to a different direction from the first scan. If a plurality of works of different sizes exist or the works are crowded together, in the first scan, a work that is not illuminated by line light may occur, for example, because it is in the shadow of another work. Alternatively, in the case of a workpiece with surface irregularities, a shadow portion in which line light is not illuminated may occur in the first scan, such as being blocked by a convex portion. However, by executing the second scan, it becomes possible to measure the height again for these shadow areas. Therefore, the height of the work can be accurately measured.

In the above workpiece height measuring device, the measurement unit sets the scanning direction to a predetermined first scan direction while setting the posture of the imaging area of the imaging unit and the irradiation direction of the line light to predetermined conditions, and performs the first scan. is executed, the scan direction is maintained in the first scan direction, the imaging area is rotated around the imaging optical axis, and the relationship between the irradiation direction of the line light and the posture of the imaging area is set to the first scan. The second scan can be performed by changing the direction of irradiation of the line light so that it remains the same.

According to this workpiece height measuring device, the first scan and the second scan are performed without changing the scan direction. Even if the scan direction is not changed, the direction of the imaging area and the line light irradiation direction are different in the first scan and the second scan. Therefore, height measurement can be performed in the second scan for the area where the workpiece height data is missing. Additionally, since the relationship between the posture of the imaging area and the line light irradiation direction remains the same in the first scan and the second scan, height data can be derived efficiently.

In the above workpiece height measuring device, the measurement unit sets the scanning direction to a predetermined first scan direction while setting the posture of the imaging area of the imaging unit and the irradiation direction of the line light to predetermined conditions, and performs the first scan. is executed, the scanning direction is set to a second scanning direction different from the first scanning direction, the imaging area is rotated around the imaging optical axis according to the second scanning direction, and the line light is irradiated in an irradiation direction and The second scan may be performed by changing the orientation of the line light irradiation direction so that the attitude relationship of the imaging area is maintained the same as in the first scan.

According to this workpiece height measuring device, height measurement can be performed in the second scan for the area where missing portions of workpiece height data occur simply by changing the scan direction.

In the above workpiece height measuring device, the scan driving section includes a first moving mechanism that horizontally moves the imaging section and the line light projection section in a first moving direction, and a second moving direction orthogonal to the first moving direction in a horizontal plane. and a second moving mechanism that moves horizontally, wherein the measuring unit selects and operates either the first moving mechanism or the second moving mechanism when performing the first scan and the second scan. do.

According to this workpiece height measuring device, when performing a scan operation, the scan drive unit drives only one of the first moving mechanism or the second moving mechanism. Accordingly, driving control of the scan driver can be simplified.

In this case, when selecting the first movement mechanism or the second movement mechanism, the measurement unit preferably selects the one with a shorter scan distance. According to this aspect, the total scan distance required to scan the work can be shortened, contributing to speeding up height measurement.

In the above workpiece height measuring device, the workpiece is a substrate on which a plurality of components are mounted, and the measurement unit acquires component mounting data including information on the shape of the component and the mounting position on the substrate, and It is desirable to determine the presence or absence of missing portions in the height data based on component mounting data.

According to this workpiece height measuring device, it becomes possible to determine in advance the relationship between the irradiation direction or scanning direction of line light and the location of missing portions in the height data based on component mounting data. Accordingly, the irradiation direction or scanning direction of the line light with few missing portions can be set in advance.

In the above workpiece height measuring device, when a missing part of the height data is detected, the measuring unit determines whether the cause of the missing part is due to the scanning direction, and if the missing part is due to the scanning direction, the It is desirable to run 2 scans.

Missing portions of height data may also occur, for example, when an opening or notch exists in the installation base of the work. According to the above-mentioned workpiece height measuring device, the second scan is performed only when there is a height data missing portion due to the scan direction. Accordingly, the second scan is not performed useless.

In the above workpiece height measuring device, the workpiece is a workpiece mounted on a loading surface of a substrate, the measuring portion specifies a data area where height data higher than the height of the loading surface is obtained, and the missing portion specifies the data. The second scan can be executed when the area is adjacent to the scan direction.

When the height data missing part is adjacent to the scan direction of the data area, there is a high possibility that the cause of the missing part is a shadow when line light is irradiated. According to the above-mentioned workpiece height measuring device, in this case, it is determined that the data missing part is the missing part due to the scanning direction. Therefore, it is possible to accurately determine whether the second scan is necessary or unnecessary.

In the above workpiece height measuring device, the measurement unit performs the second scan when the missing part adjacent to the scan direction of the data area is a missing part of less than a predetermined number of pixels in the image obtained by the first scan. It can be run.

According to this workpiece height measuring device, the standard for determining that the workpiece is the missing part, which is the trigger for executing the second scan, can be arbitrarily set according to the number of pixels.

In the above workpiece height measuring device, the workpiece is a workpiece mounted on a loading surface of a substrate, and the measurement unit measures a model substrate on which the workpiece is mounted on the substrate in a predetermined arrangement and transmits the line light to the scan driver. When a plurality of scans with different irradiation directions are executed and a work mounted on the substrate in the same arrangement as the model substrate is targeted for height measurement, a scan used as at least the first scan among the plurality of scans You can obtain height data by selecting .

According to this workpiece height measuring device, since multiple scans are performed using a model substrate, it becomes possible to detect the optimal scan in which missing height data parts are least likely to occur. In addition, the optimal scan detected in advance can be applied to the same mounting board as the model board.

In this case, the measurement unit specifies a data area in which height data higher than the height of the loading surface is obtained in the plurality of scans, and determines a missing area of the height data adjacent to the scan direction of the data area. It is preferable to calculate the area and select, as the first scan, the scan in which the area of the missing portion is smallest among the plurality of scans.

According to this workpiece height measuring device, the first scan can be performed in a scanning mode in which the occurrence area of missing portions of height data is smallest.

In the above workpiece height measuring device, the measurement unit executes the first scan for one workpiece and executes the second scan considering that there is a missing portion, and the first scan and the second scan are performed. It is desirable to obtain the height data of the single workpiece by combining the height data obtained from the image obtained.

According to this workpiece height measuring device, it is possible to obtain workpiece height data at high precision by combining height data obtained through two scans.

In the above workpiece height measuring device, the scan driving section includes a first moving mechanism that horizontally moves the imaging section and the line light projection section in a first moving direction, and a second moving direction orthogonal to the first moving direction in a horizontal plane. and a second moving mechanism that horizontally moves, wherein the first moving mechanism includes a first encoder that detects a position in the first moving direction with a predetermined resolution, and the second moving mechanism detects a position in the second moving direction. It is preferable that each second encoder detects at the predetermined resolution, and that the imaging unit captures an image of the workpiece in synchronization with the position detection signals output by the first encoder and the second encoder during scanning.

According to this workpiece height measuring device, imaging is performed in synchronization with the position detection signal output from the first and second encoders, so it becomes possible to acquire workpiece height data at the same pitch regardless of the scanning direction.

In the above work height measuring device, a slider movable in a scanning direction, a head supported on the slider and rotatably holding the imaging unit and the line light projection unit around the imaging optical axis, the imaging unit and the It is preferable to further include a rotation mechanism for rotating the line light projection unit or both separately.

According to this workpiece height measuring device, the imaging unit and the line light projection unit can be rotated together or individually. Therefore, the rotation angle of the imaging area and the irradiation direction of the line light can be freely set.

In the above workpiece height measuring device, a plurality of the line light projection units may be arranged at a predetermined pitch on a circumference centered on the imaging optical axis of one of the imaging units.

According to this work height measuring device, the irradiation direction of the line light can be changed by selecting one of a plurality of line light projection units arranged in a circumference.

A mounted board inspection device according to another aspect of the present invention includes a measurement stage into which a mounted board with components mounted is loaded, and a workpiece height measurement device that measures the height of a component on the mounted board loaded into the measurement stage as the workpiece. Equipped with equipment.

According to this mounted board inspection device, the height of a component can be accurately measured regardless of the arrangement state of the component, and thus an accurate mounted substrate inspection can be performed.

Claims (16)

an imaging unit having an imaging optical axis in a vertical direction and capturing an image of a workpiece;
a line light projection unit having a projection optical axis having a predetermined crossing angle with respect to the imaging optical axis and capable of irradiating line light from a plurality of directions with respect to the workpiece;
a scan driving unit that moves the imaging unit and the line light projection unit to scan a workpiece;
a measuring unit that controls the scan driving unit to execute the scan and obtains height data of the workpiece by an optical cutting method based on the image acquired by the scanning;
The measuring unit,
Executing a first scan by irradiating the line light to the workpiece from a predetermined irradiation direction,
In the height data obtained based on the image acquired by the first scan, determine whether there is a missing part of the height data of the work,
A workpiece height measuring device that, when the missing part is detected, performs a second scan in which the line light is irradiated in a direction different from that of the first scan. According to claim 1,
The measuring unit,
With the posture of the imaging area of the imaging unit and the irradiation direction of the line light set to predetermined conditions, the scan direction is set to a predetermined first scan direction to execute the first scan,
Maintaining the scan direction in the first scan direction, rotating the imaging area around the imaging optical axis, and maintaining the relationship between the irradiation direction of the line light and the posture of the imaging area the same as the first scan. , A workpiece height measuring device that executes the second scan by changing the direction of irradiation of the line light. According to claim 1,
The measuring unit,
With the posture of the imaging area of the imaging unit and the irradiation direction of the line light set to predetermined conditions, the scan direction is set to a predetermined first scan direction to execute the first scan,
The scanning direction is set to a second scanning direction different from the first scanning direction, the imaging area is rotated around the imaging optical axis according to the second scanning direction, and the irradiation direction of the line light and the imaging area are adjusted. A workpiece height measuring device that performs the second scan by changing the orientation of the line light irradiation direction so that the attitude relationship remains the same as in the first scan. According to claim 1,
The scan driver includes a first moving mechanism that horizontally moves the imaging unit and the line light projection unit in a first moving direction, and a second moving mechanism that horizontally moves the first moving direction and the second moving direction orthogonal to the horizontal plane. Contains,
A workpiece height measuring device in which the measurement unit selects and operates either the first movement mechanism or the second movement mechanism when performing the first scan and the second scan. According to claim 4,
A workpiece height measuring device wherein the measurement unit selects the shorter scanning distance when selecting the first moving mechanism or the second moving mechanism. The method according to any one of claims 1 to 5,
The work is a board on which a plurality of components are mounted,
A workpiece height measuring device in which the measurement unit acquires component mounting data including information on the shape of the component and its mounting position on the substrate, and determines the presence or absence of a missing part in the height data based on the component mounting data. The method according to any one of claims 1 to 5,
The measuring unit,
When a missing part of the height data is detected, determine whether the cause of the missing part is due to the scanning direction,
A work height measuring device that performs the second scan in the case of missing parts due to the scan direction. According to claim 7,
The work is a work mounted on the loading surface of the substrate,
The measuring unit,
Specifying a data area in which height data higher than the height of the loading surface is obtained,
A workpiece height measuring device that executes the second scan when the missing portion is adjacent to the scan direction of the data area. According to claim 8,
The workpiece height measuring device wherein the measurement unit performs the second scan when the missing part adjacent to the scan direction of the data area is a missing part of less than a predetermined number of pixels in the image obtained by the first scan. The method according to any one of claims 1 to 5,
The work is a work mounted on the loading surface of the substrate,
The measuring unit,
Targeting a model substrate on which the work is mounted on the substrate in a predetermined arrangement, causing the scan driver to perform a plurality of scans with the line light irradiated in different directions,
A work height measuring device that obtains height data by selecting at least a scan to be used as the first scan among the plurality of scans when a work mounted on a substrate in the same arrangement as the model substrate is to be measured. According to claim 10,
The measuring unit,
In the plurality of scans, a data area in which height data higher than the height of the loading surface is obtained is specified,
Obtain the area of the missing portion of the height data adjacent to the scan direction of the data area,
A workpiece height measuring device that selects, as the first scan, a scan in which the area of the missing portion is smallest among the plurality of scans. The method according to any one of claims 1 to 5,
The measuring unit,
Executing the first scan for one work and executing the second scan considering that there is a missing part,
A workpiece height measuring device that obtains height data of the single workpiece by combining height data obtained from images obtained by the first scan and the second scan. According to claim 1,
The scan driver includes a first moving mechanism that horizontally moves the imaging unit and the line light projection unit in a first moving direction, and a second moving mechanism that horizontally moves the first moving direction and the second moving direction orthogonal to the horizontal plane. Contains,
The first moving mechanism includes a first encoder that detects a position in the first moving direction with a predetermined resolution, and the second moving mechanism includes a second encoder that detects a position in the second moving direction with the predetermined resolution. Equipped with each,
A workpiece height measuring device in which the imaging unit captures an image of the workpiece in synchronization with position detection signals output from the first encoder and the second encoder during scanning. The method according to any one of claims 1 to 13,
A slider that can be moved in the scanning direction,
a head supported on the slider and rotatably holding the imaging unit and the line light projection unit around the imaging optical axis;
The workpiece height measuring device further includes a rotation mechanism that rotates the imaging unit and the line light projection unit together or separately. The method according to any one of claims 1 to 13,
A workpiece height measuring device in which a plurality of the line light projection units are arranged at a predetermined pitch on a circumference centered on the optical axis of the imaging unit. A measurement stage into which a mounting board with components mounted is brought in,
A mounted board inspection device comprising the workpiece height measuring device according to any one of claims 1 to 15, which measures the height of a component on the mounted board loaded into the measurement stage as the workpiece.