JP6553011B2 - Three-dimensional measuring device - Google Patents

Description

  The present invention relates to a three-dimensional measurement apparatus that performs three-dimensional measurement by a phase shift method.

  Generally, when mounting an electronic component on a printed circuit board, cream solder is first printed on a predetermined electrode pattern disposed on the printed circuit board. Next, an electronic component is temporarily fixed on the printed circuit board based on the viscosity of the cream solder. Thereafter, the printed circuit board is introduced into a reflow furnace, and soldering is performed through a predetermined reflow process. Nowadays, it is necessary to inspect the printing condition of the cream solder before being introduced to the reflow furnace, and a three-dimensional measuring device may be used for such inspection.

  Conventionally, various non-contact three-dimensional measurement devices using light have been proposed. For example, there is a three-dimensional measuring apparatus using a phase shift method.

  As a three-dimensional measurement apparatus using the phase shift method, for example, a moving mechanism that moves an object to be measured, an irradiation apparatus that irradiates the object to be measured with a striped pattern light, and an object irradiated with the pattern light. An apparatus including an imaging device that images a measurement object is known (for example, see Patent Document 1).

  In such a three-dimensional measurement apparatus, a plurality of pieces of image data in which the light intensity distribution on the measurement object is different by a predetermined phase of the pattern light by moving the measurement object relative to the measurement head including the irradiation device and the imaging device. You can get Then, it is possible to perform three-dimensional measurement of the object to be measured by the phase shift method based on the plurality of image data.

For example, when four types of image data having different light intensity distributions on the measurement object by 90 ° of the phase of the pattern light are acquired, the luminance value I _{0 at} a predetermined coordinate position on the measurement object in the four types of image data. , I ₁ , I ₂ and I ₃ can be represented by the following formulas (1), (2), (3) and (4), respectively.

I ₀ = α + βsinφ (1)
I ₁ = α + β sin (φ + 90 °) (2)
I ₂ = α + β sin (φ + 180 °) (3)
I ₃ = α + β sin (φ + 270 °) (4)
However, α: offset, β: gain, φ: phase of pattern light.

  If the above equations (1), (2), (3) and (4) are solved for the phase φ, the following equation (5) can be derived.

φ = tan ⁻¹ {(I ₀ −I ₂ ) / (I ₁ −I ₃ )} (5)
Then, using the phase φ calculated as described above, the height (Z) at each coordinate (X, Y) on the object to be measured can be obtained based on the principle of triangulation.

  As an imaging device used in the imaging apparatus, a CCD (Charge Coupled Devices) area sensor, a CMOS (Complementary Metal Oxide Semiconductor) area sensor, and the like are known.

  For example, an interline transfer type CCD area sensor is two-dimensionally arranged in a matrix, and converts a plurality of light receiving portions (pixels) that accumulate incident light into charges corresponding to the amount of light, and the light receiving portions that are stored in the light receiving portions. A plurality of vertical transfer units for transferring charges in the vertical direction, a horizontal transfer unit for transferring charges transferred from the vertical transfer unit in the horizontal direction, and converting and amplifying the charges transferred from the horizontal transfer unit to voltages And an output amplifier for outputting.

  In recent years, in the field of three-dimensional measurement, speeding up of measurement is required. To cope with this, for example, as an image sensor, an imaging area is divided into two areas on the left and right, and an area sensor that performs output from the two areas in parallel from different channels is used. It is conceivable to speed up the acquisition speed of (see, for example, Patent Document 2).

JP 2012-247375 A Unexamined-Japanese-Patent No. 2001-94886

  However, in the three-dimensional measuring apparatus as in Patent Document 1, when an image sensor having a plurality of output channels is used, it is necessary for performing three-dimensional measurement by the phase shift method at a predetermined position on the object to be measured. Multiple data (brightness values) may be acquired from different channels.

  For example, as shown in FIGS. 14A to 14D, a predetermined time Δt elapses in the measurement object 90 continuously conveyed in the right direction of the figure by the imaging device 80 having two output channels CH1 and CH2. It is assumed that imaging is performed for each time, and four types of data (brightness values) necessary to perform three-dimensional measurement by the phase shift method at a predetermined position P on the measurement object 90 are acquired.

  In the example shown in FIG. 14, the predetermined position P on the measurement object 90 is imaged in the left imaging area 80A corresponding to the first output channel CH1 at the imaging timings t1 and t2 [FIGS. 14A and 14B. Reference), at the imaging timings t3 and t4, imaging is performed in the right imaging region 80B corresponding to the second output channel CH2. That is, the predetermined position P on the measurement object 90 straddles the boundary portions (partition lines) 80C of the imaging regions 80A and 80B corresponding to the channels CH1 and CH2 during the four imaging operations, and the predetermined position P The four types of data pertaining to are acquired from two different channels.

  In an imaging device having a plurality of output channels, since the output amplifier is different for each channel, the values of gain and offset in each channel do not match exactly. That is, since the values of “α (offset)” and “β (gain)” in the above formulas (1) to (4) relating to the phase shift do not match, in the case shown in FIG. Errors may increase.

  The above problem is not necessarily limited to the measurement of height of cream solder or the like printed on a printed circuit board, but is inherent in the field of other three-dimensional measurement devices.

  The present invention has been made in view of the above circumstances, and a purpose thereof is a three-dimensional measurement apparatus capable of improving measurement efficiency and suppressing reduction in measurement accuracy when performing three-dimensional measurement by a phase shift method. To provide.

  Hereinafter, each means suitable for solving the above-mentioned subject will be described by item. In addition, the operation and effect specific to the corresponding means will be added as needed.

Means 1. An irradiation unit capable of irradiating a predetermined pattern light onto an object to be measured (for example, a printed circuit board);
A predetermined imaging region is partitioned into a plurality of regions, and includes an imaging device that performs output from the partitioned regions in parallel from different channels, and images the measurement object irradiated with the pattern light. Possible imaging means;
Moving means capable of relatively moving the irradiation means, the imaging means, and the object to be measured along a predetermined direction;
Each time the irradiation unit, the imaging unit, and the object to be measured move relative to each other by a predetermined amount under the pattern light emitted from the irradiation unit, the same area among the plurality of areas in the imaging device Data acquisition means capable of acquiring a plurality of data relating to each coordinate position on the object to be imaged;
Data processing means capable of performing three-dimensional measurement on each coordinate position on the object to be measured by a phase shift method based on the plurality of data acquired by the data acquisition means. Former measuring device.

  According to the means 1, for example, pattern light having a striped (sinusoidal) light intensity distribution is irradiated onto an object to be continuously conveyed, and the object to be measured irradiated with the pattern light has a predetermined amount (for example, Each time the pattern light is transported (distance corresponding to 90 ° phase of the pattern light), the image is picked up by the image pickup means. As a result, a plurality of sets of image data are acquired in which the phase of the irradiated pattern light differs by a predetermined amount (for example, by 90 °). Then, three-dimensional measurement of the object to be measured is performed based on these image data.

  Further, in this means, an imaging device is used in which the imaging region is partitioned into a plurality of regions and outputs from the partitioned regions are performed in parallel from different channels. As a result, the imaging speed (image data acquisition speed) can be increased, and the measurement efficiency can be improved.

  In addition, this means is configured to perform three-dimensional measurement by the phase shift method for each coordinate position on the object to be measured based on a plurality of data acquired from the same channel of the image sensor. For this reason, the values of “α (offset)” and “β (gain)” in the above equations (1) to (4) relating to the phase shift coincide with each other, and the reduction in measurement accuracy can be suppressed.

  Means 2. 2. The three-dimensional measuring apparatus according to claim 1, wherein the imaging element is provided such that a partition line (a boundary portion of the plurality of regions) dividing the plurality of regions is along the predetermined direction.

  According to the above means 2, in the imaging device, there is no partition line orthogonal to the predetermined direction (the relative movement direction of the irradiation means and imaging means and the object to be measured), and there are a plurality of regions in the direction orthogonal to the predetermined direction. It becomes the structure arranged in parallel. Thus, the entire area in the predetermined direction of the imaging device can be utilized for data acquisition. As a result, it is possible to increase the relative movement speed between the irradiation means and the imaging means and the object to be measured, and the measurement efficiency can be further improved.

Means 3. A first irradiation unit capable of irradiating a predetermined pattern light onto an object to be measured;
A second irradiating unit capable of irradiating a second light different from the pattern light to the object to be measured;
A predetermined imaging area is divided into a plurality of areas, and has an imaging element that performs output from the divided areas in parallel from different channels, and images the measurement object irradiated with the various lights. Possible imaging means;
Moving means capable of relatively moving the two irradiation means, the imaging means, and the object to be measured along a predetermined direction;
Under the pattern light emitted from the first irradiation means, each of the two irradiation means, the imaging means, and the object to be measured moves by a predetermined amount relative to each other among the plurality of areas in the imaging device. First data acquisition means capable of acquiring a plurality of data relating to each coordinate position on the object to be measured which is imaged in a first area (for example, an area on the upstream side in a predetermined direction);
First data processing means capable of executing three-dimensional measurement relating to each coordinate position on the measurement object by a phase shift method based on the plurality of data acquired by the first data acquisition means;
A second region (for example, a downstream region in a predetermined direction) that is different from the first region in the predetermined direction among the plurality of regions in the image sensor under the second light irradiated from the second irradiation unit. A second data acquisition unit capable of acquiring data captured in
A three-dimensional measurement apparatus comprising: second data processing means capable of executing predetermined processing based on data acquired by the second data acquisition means.

  According to the above means 3, the same function and effect as the above means 1 can be obtained. Furthermore, in this means, in addition to the imaging in the first area for the purpose of three-dimensional measurement, the imaging in the second area is performed under the second light. That is, in addition to the acquisition of data for three-dimensional measurement, it is possible to acquire data used for other purposes different from the three-dimensional measurement (data for executing a predetermined process by the second data processing means).

  As a result, a plurality of types of measurement can be combined and measurement accuracy can be further improved. In addition, since imaging in the first area and imaging in the second area can be performed simultaneously, simplification of imaging processing and suppression of reduction in measurement efficiency can be achieved.

  Means 4. The three-dimensional measurement device according to the means 3, wherein the second irradiation unit is configured to be capable of irradiating uniform light having a constant light intensity as the second light.

  According to the means 4, it is possible to acquire luminance image data by irradiating uniform light. As a result, it is possible to perform mapping on 3D data obtained by, for example, 3D measurement based on the luminance image data, and to extract a measurement area, thereby further improving measurement accuracy and the like. Can.

  Means 5. The three-dimensional measurement device according to the means 3, wherein the second irradiation unit is configured to be capable of irradiating a predetermined pattern light as the second light.

  According to the means 5, it becomes possible to newly perform three-dimensional measurement different from the three-dimensional measurement based on the pattern light emitted from the first irradiation means, and further improve the measurement accuracy.

  For example, an average value of a measurement result obtained by three-dimensional measurement based on a plurality of data acquired in the first area of the image sensor and a measurement result obtained by three-dimensional measurement based on a plurality of data acquired in the second area of the image sensor Thus, the measurement accuracy can be improved.

  Further, if pattern light having a luminance different from that of the pattern light emitted from the first irradiation means is irradiated as “second light”, various problems may occur due to differences in brightness of each part on the measurement object. It can be suppressed. For example, since the light reflectance and the like differ between the printed portion (solder printed area) of the cream solder and the other portion (background area) on the printed circuit board, under pattern light of the same brightness, each portion is more accurate It may be difficult to obtain such data.

  Means 6. The three-dimensional measurement device according to any one of the means 1 to 5, wherein the object to be measured is a printed circuit board on which cream solder is printed, or a wafer substrate on which solder bumps are formed.

  According to the above-mentioned means 6, height measurement etc. of cream solder printed on a printed circuit board or a solder bump formed in a wafer board can be performed. As a result, in the inspection of the cream solder or the solder bump, the quality determination of the cream solder or the solder bump can be performed based on the measured value. Therefore, in the inspection, the operation and effect of each of the above-described means are exhibited, and the quality determination can be performed with high accuracy. As a result, it is possible to improve the inspection accuracy in the solder printing inspection apparatus or the solder bump inspection apparatus.

It is a schematic perspective view which shows a board | substrate inspection apparatus typically. It is a sectional view of a printed circuit board. It is a block diagram which shows the electric constitution of a board | substrate inspection apparatus. It is the figure which showed typically the aspect of the pattern light irradiated on the printed circuit board. It is a schematic diagram which shows schematic structure of a CCD area sensor. It is a schematic diagram for demonstrating the relationship between the coordinate position on the printed circuit board which changes with progress of time, and the imaging range of a camera. It is a table | surface for demonstrating the relationship between the coordinate position on a printed circuit board which changes with progress of time, and the phase of pattern light. It is the table | surface which showed typically the state which aligned the coordinate position of several image data. It is the table | surface which showed typically the state which arranged the data concerning each coordinate position of a printed circuit board. (A)-(d) is a schematic diagram for demonstrating the positional relationship of the printed circuit board and image pick-up element in image pick-up timing t1, t2, t3, t4. It is a schematic diagram which shows schematic structure of the image pick-up element which concerns on another embodiment. It is a schematic diagram which shows schematic structure of the image pick-up element which concerns on another embodiment. (A)-(d) is a schematic diagram for demonstrating the positional relationship of the printed circuit board in imaging timing t1, t2, t3, and t4, and the image pick-up element concerning another embodiment. (A)-(d) is a schematic diagram for demonstrating the positional relationship of the printed circuit board and image pick-up element in image pick-up timing t1, t2, t3, t4.

  Hereinafter, an embodiment will be described with reference to the drawings. First, the configuration of a printed circuit board as an object to be measured will be described in detail.

  As shown in FIG. 2, the printed board 1 has a flat plate shape, and an electrode pattern 3 made of copper foil is provided on a base board 2 made of glass epoxy resin or the like. Further, cream solder 4 is printed on the predetermined electrode pattern 3. The area where the cream solder 4 is printed is referred to as “solder printing area”. The portion other than the solder printing area is collectively referred to as a “background area”. The background area includes an area where the electrode pattern 3 is exposed (symbol E1), an area where the base substrate 2 is exposed (symbol E2), and the base substrate 2 A region (symbol E3) coated with the resist film 5 and a region (symbol E4) coated with the resist film 5 on the electrode pattern 3 are included. The resist film 5 is coated on the surface of the printed circuit board 1 so that the cream solder 4 does not rest on other than the predetermined wiring portion.

  Next, the configuration of the substrate inspection apparatus including the three-dimensional measurement apparatus according to this embodiment will be described in detail. FIG. 1 is a schematic configuration view schematically showing a substrate inspection apparatus 10.

  The substrate inspection apparatus 10 includes a conveyor 13 as a conveying means (moving means) for conveying the printed circuit board 1, an illumination device 14 as an irradiating means for irradiating predetermined light on the surface of the printed circuit board 1 from above, To perform various controls, image processing, and arithmetic processing in the substrate inspection apparatus 10 such as drive control of the camera 15 and the conveyor 13, the illumination device 14, and the camera 15 as imaging means for imaging the printed circuit board 1 irradiated with light. The control device 16 (see FIG. 3). The control device 16 constitutes data acquisition means and data processing means in the present embodiment.

  The conveyor 13 is provided with driving means such as a motor (not shown), and the motor is driven and controlled by the control device 16 so that the printed circuit board 1 placed on the conveyor 13 is in a predetermined direction (FIG. 1 right Direction) at a constant speed. As a result, the imaging range W of the camera 15 moves relative to the printed circuit board 1 in the reverse direction (left direction in FIG. 1).

  The illuminating device 14 includes a light source that emits predetermined light and a grating (liquid crystal panel or the like) that converts light from the light source into pattern light, and has a striped (sinusoidal) light intensity distribution with respect to the printed circuit board 1. It is comprised so that irradiation of pattern light is possible.

  As shown in FIG. 4, in the present embodiment, pattern light in which the direction of the stripes is orthogonal to the substrate conveyance direction (X direction) is irradiated on the printed substrate 1 to be conveyed. That is, pattern light in which the direction of the stripes is parallel to the direction (Y direction) orthogonal to the substrate transfer direction (X direction) is irradiated.

  The camera 15 includes a lens 15a, an imaging element 15b, and the like, and its optical axis is set along a direction (Z direction) perpendicular to the printed circuit board 1 placed on the conveyor 13. In the present embodiment, an interline transfer type CCD area sensor 30 is adopted as the image pickup element 15b of the camera 15 (see FIG. 5).

  As shown in FIG. 5, the CCD area sensor 30 includes a plurality of light receiving units that are two-dimensionally arranged in a matrix and that are formed by photoelectric conversion elements (for example, photodiodes) that convert incident light into charges corresponding to the amount of light. (Pixels) 31 are provided corresponding to each vertical column of the light receiving unit 31, and the charges accumulated in the light receiving units 31 of the vertical column are sequentially transferred by one row (one pixel) in the vertical direction. A plurality of vertical transfer units (vertical CCD shift registers) 32, a horizontal transfer unit (horizontal CCD shift register) 33 for sequentially transferring the charges for one row transferred from the vertical transfer unit 32 in the horizontal direction, and the horizontal An output amplifier 35 that converts the electric charge transferred from the transfer unit 33 into a voltage, amplifies it, and outputs it is provided.

  In the present embodiment, the horizontal direction of the CCD area sensor 30 is along the X direction, which is the substrate transport direction, and the vertical direction of the CCD area sensor 30 is along the Y direction orthogonal to the substrate transport direction (X direction). The camera 15 is disposed.

  Further, as shown in FIG. 5, the CCD area sensor 30 according to the present embodiment has an imaging area 38 for one screen divided into two in the vertical direction (Y direction) around the optical axis of the camera 15 (in two). And the output from the two divided areas is performed in parallel from two different channels.

  More specifically, the charges read from the light receiving unit 31 included in the first imaging region 38A positioned on the upper side (the rear side in FIG. 5) of FIG. 5 are illustrated via the first horizontal transfer unit 33A on the upper side of FIG. 5 is output from the first output amplifier 35A on the upper side. The output path is the first channel CH1.

  On the other hand, the charges read from the light receiving unit 31 included in the second imaging region 38B located on the lower side (front side in FIG. 1) of FIG. 5 are transmitted via the second horizontal transfer unit 33B on the lower side of FIG. 5 is output from the second output amplifier 35B on the lower side. The output path is the second channel CH2.

  The image signals (image data) respectively output from both channels CH1 and CH2 are synthesized as an image signal (image data) for one screen captured by the entire imaging region 38 via a circuit (not shown) and the like. After being converted into a digital signal, it is output from the camera 15 to the control device 16. The image data input to the control device 16 is stored in an image data storage device 24 described later. Then, the control device 16 performs image processing, calculation processing, and the like as described later based on the image data.

  Next, the electrical configuration of the control device 16 will be described in detail with reference to FIG. FIG. 3 is a block diagram showing the electrical configuration of the substrate inspection apparatus 10. As shown in FIG.

  As shown in FIG. 3, the control device 16 includes a CPU and an input / output interface 21 that control the entire board inspection apparatus 10, an input device 22 as an “input means” configured by a keyboard, a mouse, a touch panel, and the like, a CRT, A display device 23 as a “display unit” having a display screen such as a liquid crystal, an image data storage device 24 for storing image data captured and acquired by the camera 15, and a three-dimensional image obtained based on the image data An operation result storage device 25 for storing various operation results such as measurement results, and a setting data storage device 26 for previously storing various information such as design data are provided. Each of these devices 22 to 26 is electrically connected to the CPU and the input / output interface 21.

  Next, various processing such as three-dimensional measurement processing executed by the substrate inspection apparatus 10 will be described in detail.

  The control device 16 drives and controls the conveyor 13 to continuously convey the printed circuit board 1 at a constant speed. Then, the control device 16 drives and controls the lighting device 14 and the camera 15 based on a signal from an encoder (not shown) provided on the conveyor 13.

  More specifically, each time the printed circuit board 1 is transported by a predetermined amount Δx, that is, each time a predetermined time Δt elapses, the printed circuit board 1 irradiated with the pattern light is imaged by the camera 15. Every time the predetermined time Δt elapses, the image data captured and acquired by the camera 15 is transferred to the control device 16 as needed, and stored in the image data storage device 24.

  In the present embodiment, the predetermined amount Δx is set to a distance corresponding to a phase of 90 ° of the pattern light emitted from the illumination device 14. Further, the imaging range W of the camera 15 in the substrate transport direction (X direction) is set to a length corresponding to one cycle (phase 360 °) of the pattern light. Of course, the predetermined amount Δx and the imaging range W of the camera 15 are not limited to this, and may be longer or shorter.

  Here, the relationship between the pattern light emitted from the illumination device 14 and the printed circuit board 1 imaged by the camera 15 will be described in detail by giving a specific example. FIG. 6 is a schematic diagram for explaining the relationship between the coordinate position on the printed circuit board 1 which moves relative to the passage of time and the imaging range W of the camera 15. As shown in FIG. FIG. 7 is a table for explaining the relationship between the coordinate position on the printed circuit board 1 which moves relative to the passage of time and the phase of the pattern light.

  As shown in FIGS. 6 and 7, at a predetermined imaging timing t <b> 1, a range corresponding to coordinates P <b> 2 to P <b> 17 in the board transport direction (X direction) of the printed board 1 is within the imaging range W of the camera 15. To position. That is, at the imaging timing t1, the image data in the range of the coordinates P2 to P17 on the surface of the printed circuit board 1 irradiated with the pattern light is acquired.

  As shown in FIG. 7, at the imaging timing t1, the phase of the pattern light irradiated onto the printed circuit board 1 is “0 °” at the coordinate P17, “22.5 °” at the coordinate P16, and “45 °” at the coordinate P15. ... Image data in which the phase of the pattern light is shifted by “22.5 °” for each of the coordinates P2 to P17, such as “360 ° (0 °)” at the coordinate P1. However, the phase of the pattern light shown in FIG. 7 is assumed to be a case where the reference position having a height position “0” and a plane is irradiated.

  As for the direction (Y direction) orthogonal to the board conveyance direction (X direction) on the printed board 1, the entire Y direction range of the printed board 1 is included in the imaging range of the camera 15, and the same coordinate position in the X direction. There is no difference in the phase of the pattern light for each coordinate position in the Y direction in. Since the positional relationship between the camera 15 and the illumination device 14 is fixed, the phase of the pattern light emitted from the illumination device 14 is fixed with respect to each coordinate position of the image sensor 15b (CCD area sensor 30). .

  At an imaging timing t2 when a predetermined time Δt has elapsed from the imaging timing t1, a range corresponding to coordinates P6 to P21 on the printed circuit board 1 is located in the imaging range W of the camera 15, and image data in the range is acquired. Ru.

  At the imaging timing t3 when the predetermined time Δt has elapsed from the imaging timing t2, a range corresponding to the coordinates P10 to P25 of the printed circuit board 1 is located in the imaging range W of the camera 15, and image data in the range is acquired. .

  At the imaging timing t4 when the predetermined time Δt has elapsed from the imaging timing t3, a range corresponding to the coordinates P14 to P29 of the printed circuit board 1 is located in the imaging range W of the camera 15, and image data in the range is acquired. .

  Thereafter, every time the predetermined time Δt elapses, the same process as the process of the imaging timings t1 to t4 is repeatedly performed.

  Note that the imaging element 15b (CCD area sensor 30) according to the present embodiment is arranged so that the partition line (boundary portion) 38C of the first imaging area 38A and the second imaging area 38B is along the substrate transport direction (X direction). It is done. Therefore, in the present embodiment, as shown in FIGS. 10A to 10D, the first output is generated for all four imagings (imaging timings t1, t2, t3, and t4) at the predetermined position P of the printed circuit board 1 The image is captured in the first imaging region 38A corresponding to the channel CH1. That is, four types of data (brightness values) necessary for performing three-dimensional measurement by the phase shift method at the predetermined position P of the printed circuit board 1 are obtained from the same channel.

  When all the data relating to the predetermined coordinate position (for example, coordinate P17) of the printed circuit board 1 is acquired in this way, the coordinate positions of the image data are aligned (the coordinate system between the image data). Perform alignment processing (see FIG. 8). FIG. 8 is a table schematically showing a state in which the coordinate positions of a plurality of image data acquired at imaging timings t1 to t4 are aligned.

  Subsequently, various data relating to the same coordinate position of a plurality of image data are put together for each coordinate position and stored in the calculation result storage device 25 (see FIG. 9). FIG. 9 is a table schematically showing a state in which various data relating to each coordinate position of the printed circuit board 1 are arranged and rearranged. However, in FIG. 9, only the part which concerns on the coordinate P17 of the printed circuit board 1 is illustrated. Thus, in the present embodiment, four types of luminance data in which the phase of the pattern light is shifted by 90 ° are acquired at each coordinate position of the printed circuit board 1.

  Next, based on the four kinds of image data (four kinds of luminance values of each coordinate) acquired as described above, the control device 16 uses the known phase shift method shown in the background art to determine the height for each coordinate. Make a measurement. The control device 16 calculates height data of the entire printed circuit board 1 by repeating the process for each coordinate, and stores the data in the calculation result storage device 25 as three-dimensional data of the printed circuit board 1.

  And the control apparatus 16 determines the quality of the printing state of the cream solder 4 based on the measurement result obtained as mentioned above. Specifically, the control device 16 detects the print range of the cream solder 4 that has become higher than the height reference plane by a predetermined length or more, and integrates the height of each part within this range to perform printing. Calculate the amount of cream solder 4.

  Subsequently, the control device 16 sets the data such as the position, area, height or amount of the cream solder 4 thus obtained as reference data (gerber data etc.) stored in advance in the setting data storage device 26. The comparison determination is made, and the quality of the printed state of the cream solder 4 is determined depending on whether the comparison result is within the allowable range.

  As described above in detail, in the present embodiment, the pattern light having a stripe-like light intensity distribution is irradiated to the print substrate 1 which is continuously conveyed, and the print substrate 1 irradiated with the pattern light is conveyed by a predetermined amount. The camera 15 picks up an image each time it Thereby, four types of image data in which the phase of the irradiated pattern light is different by 90 ° are acquired. And three-dimensional measurement of the printed circuit board 1 is performed based on these image data.

  Furthermore, in the present embodiment, as the imaging element 15b of the camera 15, the imaging area 38 for one screen is divided into two in the vertical direction (Y direction) with the optical axis of the camera 15 as a center. The CCD area sensor 30 is used which performs the output in parallel from two different channels CH1 and CH2. As a result, the imaging speed (image data acquisition speed) can be increased, and the measurement efficiency can be improved.

  In addition, the imaging element 15b (CCD area sensor 30) according to the present embodiment is arranged such that a boundary portion (partition line) 38C between the first imaging region 38A and the second imaging region 38B is along the substrate transport direction. . And it is the structure which performs the three-dimensional measurement by the phase shift method about each coordinate position on the printed circuit board 1 based on the some data acquired from the same channel of the image pick-up element 15b (CCD area sensor 30). For this reason, the values of “α (offset)” and “β (gain)” in the above equations (1) to (4) relating to the phase shift coincide with each other, and the reduction in measurement accuracy can be suppressed.

  In addition, it is not limited to the description content of the said embodiment, For example, you may implement as follows. Of course, other applications and modifications not illustrated below are naturally possible.

  (A) In the above embodiment, the three-dimensional measurement device is embodied in the substrate inspection device 10 that measures the height of the cream solder 4 printed on the printed circuit board 1, but the present invention is not limited thereto. The present invention may be embodied in a configuration for measuring the height of other things, such as printed solder bumps and electronic components mounted on a substrate.

  (B) In the above embodiment, the printed circuit board 1 is continuously moved by the conveyor 13 so that the positional relationship between the lighting device 14 and the camera 15 and the printed circuit board 1 is relatively moved. The measuring head including the illumination device 14 and the camera 15 may be moved to relatively move the positional relationship with the printed circuit board 1.

  (C) In the above embodiment, when performing three-dimensional measurement by the phase shift method, four types of image data having different phase of the pattern light by 90 ° are obtained. The amount is not limited to these. Other phase shift times and phase shift amounts that can be three-dimensionally measured by the phase shift method may be employed.

  For example, three types of image data with different phases of 120 ° (or 90 °) may be acquired to perform three-dimensional measurement, or two types of image data with different phases of 180 ° (or 90 °) may be acquired. Then, it may be configured to perform three-dimensional measurement.

  (D) In the above embodiment, the interline transfer type CCD area sensor 30 is employed as the imaging element 15b of the camera 15. The configuration of the imaging element 15b is not limited to this.

  For example, a CCD area sensor such as a full frame transfer method, a frame transfer method, or a frame interline transfer method may be employed. Of course, not only the CCD area sensor but also a CMOS area sensor or the like may be employed.

  When a general CCD area sensor or the like is used, data transfer cannot be performed during exposure. Therefore, when imaging (exposure) is performed every time the printed circuit board 1 is conveyed by a predetermined amount as in the above embodiment. In the meantime, data transfer (reading) needs to be performed.

  On the other hand, when a CMOS area sensor or a CCD area sensor having a function capable of exposure during data transfer is used, imaging (exposure) and data transfer can be partially overlapped. Therefore, it is suitable for the continuous conveyance of the printed circuit board 1, and the measurement efficiency can be improved.

  (E) In the above embodiment, the CCD area sensor 30 is employed in which the imaging region 38 is divided into two in the Y direction, and outputs from the two divided regions are performed in parallel from two different channels CH1 and CH2, respectively. ing. The number of channels and the division configuration of the imaging area are not limited to the above embodiment, and other configurations may be adopted. For example, an imaging device (area sensor) in which an imaging region is divided into three or more regions may be adopted.

  A specific example is shown in FIG. The image pickup device 60 shown in the figure has a configuration in which an image pickup region is divided into four in the Y direction, and outputs from the four regions are performed in parallel from four different channels CH1, CH2, CH3, and CH4, respectively. The image pickup device 60 is configured so that the partition lines (boundaries of the plurality of regions) 60a, 60b, and 60c that divide the image pickup region into a plurality of regions corresponding to the channels CH1 to CH4 are all along the substrate transport direction (X direction). It is provided.

  Moreover, the example shown to FIG. 12, 13 is mentioned as another specific example. The image pickup element 70 shown in the figure has an image pickup area 78 for one screen divided into two in total in the horizontal direction and the vertical direction about the optical axis of the camera 15 by dividing lines 78E and 78F. The output from the area is performed in parallel from four different channels CH1, CH2, CH3 and CH4.

  More specifically, the charge read from the light receiving unit 71A included in the first imaging region 78A located at the upper right of FIG. 12 is transmitted to the first output amplifier via the predetermined vertical transfer unit 72A and the first horizontal transfer unit 73A. It is output from 75A. Such an output path is the first channel CH1.

  The charges read from the light receiving unit 71B included in the second imaging region 78B located in the lower right of FIG. 12 are output from the second output amplifier 75B via the predetermined vertical transfer unit 72B and the second horizontal transfer unit 73B. Be done. The output path is the second channel CH2.

  The charges read from the light receiving unit 71C included in the third imaging region 78C located in the upper left of FIG. 12 are output from the third output amplifier 75C via the predetermined vertical transfer unit 72C and the third horizontal transfer unit 73C. Ru. The output path is the third channel CH3.

  The charges read from the light receiving unit 71D included in the fourth imaging region 78D located in the lower left of FIG. 12 are output from the fourth output amplifier 75D via the predetermined vertical transfer unit 72D and the fourth horizontal transfer unit 73D. Ru. The output path is the fourth channel CH4.

  However, the imaging element 70 has a partition line 78E extending along a direction (Y direction) orthogonal to the substrate transport direction (X direction), and the imaging region 78 is divided into two in the substrate transport direction. Therefore, when acquiring four types of data (luminance values) necessary for performing the three-dimensional measurement by the phase shift method at the predetermined position P on the printed circuit board 1 by the imaging element 70, for example, the first imaging region 78A. And at least one cycle (360 ° phase) of the pattern light is projected within the width in the X direction of the second imaging region 78B.

  Then, as shown in FIGS. 13A to 13D, every time a predetermined time Δt passes through the printed circuit board 1 continuously conveyed in the right direction in the figure (for example, the printed circuit board 1 has a pattern light phase of 90 °). Each time the camera moves a distance corresponding to 1), and the first imaging corresponding to the first output channel CH1 in all four imagings (imaging timings t1, t2, t3, and t4) at the predetermined position P of the printed board 1 An image is taken within the area 78A.

  Further, the configuration is such that the partition line 78F is omitted from the imaging element 70, the first imaging area 78A and the second imaging area 78B are one area, and the third imaging area 78C and the fourth imaging area 78D are one area. It may be That is, similarly to the section configuration of the imaging element 80 shown in FIG. 14, the imaging area 78 is divided into two in the substrate transport direction (X direction) by the dividing line 78E, and the outputs from the two areas are respectively obtained from two different channels. The configuration may be performed in parallel.

  Even in such a configuration, as in the case shown in FIGS. 13A to 13D, at least one cycle (phase 360 °) of the pattern light is projected within the X-direction width of one region. If the predetermined position P of the printed circuit board 1 is imaged in the one area in all four imaging operations (imaging timings t1, t2, t3, and t4), a decrease in measurement accuracy can be suppressed. .

  (F) The configuration of the lighting device 14 is not limited to the above embodiment. For example, it is also possible to have a configuration including a first illumination as a first irradiation unit capable of irradiating a predetermined pattern light and a second illumination as a second irradiation unit capable of irradiating a second light different from the pattern light. Good.

  Under such a configuration, for example, by using the imaging element 70 in which the imaging area is divided in the board conveyance direction (X direction), a predetermined area on the printed circuit board 1 irradiated with the pattern light from the first illumination is displayed on the imaging element 70. The second region of the image sensor 70 is a region other than the first region (for example, the first imaging region 78A and the second imaging region 78B) on the printed circuit board 1 irradiated with the second light from the second illumination. It is good also as a structure imaged by (For example, the 3rd imaging area 78C and the 4th imaging area 78D).

  The function of acquiring data by imaging in the first region of the image sensor 70 constitutes the first data acquisition means in the present embodiment, and the function of performing three-dimensional measurement by the phase shift method based on the acquired data Thus, the first data processing means in the present embodiment is configured. Further, the function of acquiring data by imaging in the second region of the image sensor 70 constitutes the second data acquisition means in the present embodiment, and the function of executing predetermined processing based on the data acquired thereby enables The second data processing means in the embodiment is configured.

  Here, the “second light” may be configured to irradiate uniform light having a constant light intensity. With this configuration, it is possible to acquire luminance image data. As a result, for example, it is possible to perform mapping on three-dimensional data obtained by three-dimensional measurement, extraction of a measurement region, and the like based on the luminance image data, thereby further improving measurement accuracy and the like. .

  In addition, as the “second light”, a configuration capable of irradiating a predetermined pattern light may be used. With this configuration, apart from the first three-dimensional measurement based on the pattern light emitted from the first illumination, it is possible to perform the second three-dimensional measurement based on the pattern light emitted from the second illumination. The measurement accuracy can be improved.

  For example, for a predetermined position P of the printed circuit board 1, a measurement result obtained by three-dimensional measurement based on a plurality of data acquired in a first area (for example, the first imaging area 78A and the second imaging area 78B) of the imaging element 70, and imaging Measurement accuracy is improved by, for example, obtaining an average value of measurement results obtained by three-dimensional measurement based on a plurality of data acquired in the second region (for example, the third imaging region 78C and the fourth imaging region 78D) of the element 70. Can be

  In particular, if pattern light having a luminance different from that of the pattern light emitted from the first illumination is emitted from the second illumination as the “second light”, various problems based on the difference in brightness of each part on the printed circuit board 1 are caused. Occurrence can be suppressed. For example, the brightness of the pattern light of the first illumination is set to a relatively bright first brightness corresponding to the “background region” that is the “dark part”, while the brightness of the pattern light of the second illumination is the “bright part”. One example is to set the second luminance that is darker than the first luminance, corresponding to the “solder print area”.

  When the imaging device 70 or the like in which the imaging region is divided in the substrate conveyance direction (X direction) is used, the second region (for example, the third imaging region 78C and the fourth imaging region 78D) of the imaging device 70 is necessarily required. It is not necessary to acquire data, and the second illumination and the like may be omitted, and only data acquisition by the first area (for example, the first imaging area 78A and the second imaging area 78B) of the imaging device 70 may be performed. Thereby, simplification of data processing and reduction of processing load can be achieved.

  DESCRIPTION OF SYMBOLS 1 ... Printed circuit board, 4 ... Cream solder, 10 ... Board | substrate test | inspection apparatus, 13 ... Conveyor, 14 ... Lighting apparatus, 15 ... Camera, 15b ... Image pick-up element, 16 ... Control apparatus, 24 ... Image data storage apparatus, 25 ... Calculation result Storage device, 30 ... CCD area sensor, 38 ... imaging area, 38A ... first imaging area, 38B ... second imaging area, 38C ... partition line (boundary), CH1 ... first channel, CH2 ... second channel, W ... imaging range.

Claims (6)

An irradiation unit capable of irradiating a predetermined pattern light onto an object to be measured;
A predetermined imaging region is partitioned into a plurality of regions, and includes an imaging device that performs output from the partitioned regions in parallel from different channels, and images the measurement object irradiated with the pattern light. Possible imaging means;
Moving means capable of relatively moving the irradiation means, the imaging means, and the object to be measured along a predetermined direction;
Each time the irradiation unit, the imaging unit, and the object to be measured move relative to each other by a predetermined amount under the pattern light emitted from the irradiation unit, the same area among the plurality of areas in the imaging device Data acquisition means capable of acquiring a plurality of data relating to each coordinate position on the object to be imaged;
Data processing means capable of performing three-dimensional measurement on each coordinate position on the object to be measured by a phase shift method based on the plurality of data acquired by the data acquisition means. Former measuring device.   The three-dimensional measurement apparatus according to claim 1, wherein the image pickup element is provided such that division lines dividing the plurality of areas are along the predetermined direction. A first irradiation unit capable of irradiating a predetermined pattern light onto an object to be measured;
A second irradiating unit capable of irradiating a second light different from the pattern light to the object to be measured;
A predetermined imaging area is divided into a plurality of areas, and has an imaging element that performs output from the divided areas in parallel from different channels, and images the measurement object irradiated with the various lights. Possible imaging means;
Moving means capable of relatively moving the two irradiation means, the imaging means, and the object to be measured along a predetermined direction;
Under the pattern light emitted from the first irradiation means, each of the two irradiation means, the imaging means, and the object to be measured moves by a predetermined amount relative to each other among the plurality of areas in the imaging device. First data acquisition means capable of acquiring a plurality of data relating to each coordinate position on the object to be measured which is imaged in a first area;
First data processing means capable of executing three-dimensional measurement relating to each coordinate position on the measurement object by a phase shift method based on the plurality of data acquired by the first data acquisition means;
Under the second light emitted from the second irradiating means, among the plurality of areas in the imaging device, data captured in a second area different from the first area in the predetermined direction is acquired Possible second data acquisition means;
A three-dimensional measurement apparatus comprising: second data processing means capable of executing predetermined processing based on data acquired by the second data acquisition means.   The three-dimensional measurement apparatus according to claim 3, wherein the second irradiation unit is configured to be capable of irradiating uniform light having a constant light intensity as the second light.   The three-dimensional measurement apparatus according to claim 3, wherein the second irradiation unit is configured to be capable of irradiating a predetermined pattern light as the second light.   The three-dimensional measurement device according to any one of claims 1 to 5, wherein the object to be measured is a printed circuit board on which cream solder is printed, or a wafer substrate on which solder bumps are formed. .

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