CN105865359A - Plate bending measuring device and plate bending measuring method thereof - Google Patents

Abstract

The invention discloses a plate bending measuring device and a plate bending measuring method thereof. The plate bending measurement method comprises the following steps: projecting an image on an object to be measured, wherein the image comprises a plurality of reference points; capturing a measurement image when the image is projected on an object to be measured by an image capturing module, wherein the measurement image comprises a plurality of measurement points which respectively correspond to reference points; calculating the position of each measuring point in the measuring image through the transfer function of each reference point in the corresponding reference points to obtain the height of the object to be measured at the position of the corresponding measuring point; and compensating the bending condition of the object to be measured according to the height of the object to be measured at the position corresponding to the measuring point. Accordingly, the height of the measuring point corresponding to the object to be measured can be obtained, the optical focal length compensation can be rapidly carried out, and the reference point pattern can be transformed in a digital projection mode, so that the local plate bending can be obtained according to the position of the local reference point, and the corresponding height compensation can be carried out.

Description

Plate bending measuring device and its plate bending measuring method

technical field

The invention relates to a plate bending measuring device, and in particular to a plate bending measuring device with a projection module projecting an image on an object to be measured.

Background technique

In recent years, due to the reduction in the size of components, many automated high-precision testing equipment have been developed to detect whether the appearance, line connection, and alignment relationship of electronic components are proper. Among them, the automatic solder paste inspection machine (Solder Paste Inspection, SPI) has been widely used in the production line to accurately measure the amount of solder paste on the substrate, as a necessary tool for the control of the printed circuit board process.

In practical applications, printed circuit boards may be bent due to external stress or gravity. The plate bending phenomenon will lead to a decrease in the accuracy of the measuring device 200 in measuring the object to be measured. For example, because the object to be measured is offset in the vertical direction due to the plate bending, the part of the object to be measured that is scheduled to be measured will not be captured. At the best imaging focal length in the module, resulting in blurred images.

The traditional way to measure the bending of the board can be through the triangulation measurement method, using the laser to project the object to be measured and calculate the height of the object to be measured through the reflected laser, and then judge whether the object to be measured has a board bending. However, the laser method can only calculate the height of a small part of the object to be measured. Therefore, to obtain the entire height of the object to be measured, the laser must be projected on each part of the object to be measured in sequence, and this method will lead to measurement The time efficiency is too poor and takes too much time.

Contents of the invention

Therefore, in order to solve the above problems, the present invention is to provide a bending measurement method and a bending measuring device for improving the efficiency and accuracy of measuring the bending of the object to be measured.

One aspect of the present invention is to provide a method for measuring plate bending. The plate bending measurement method is used for measuring the object to be measured, wherein the object to be measured is placed on a measuring carrier. The plate bending measurement method includes: projecting an image on the object to be measured, wherein the image includes multiple reference points; capturing the measurement image when the image is projected on the object to be measured by the imaging module, wherein the measurement image includes multiple quantities The measuring points respectively correspond to the reference points; the position of each of the measuring points in the measurement image is calculated by the conversion function corresponding to each of the reference points to obtain the object to be measured at the height corresponding to the position of the measuring point; and generating a plate bending compensation image corresponding to the measuring object according to the height of the measuring object at the position corresponding to the measuring point, so as to compensate the plate bending of the measuring object.

According to an embodiment of the present invention, before measuring the object to be measured, the plate bending measurement method includes: projecting the image on a calibration plate placed on the measurement carrier; When the module has multiple calibration heights relative to the calibration plate, multiple calibration images when the image is projected on the calibration plate are captured by the imaging module, wherein each calibration image in the calibration images includes multiple The calibration points respectively correspond to the reference points; measure the height of each of the calibration points in the corresponding calibration image; and according to the height corresponding to the same reference point in each of the calibration images The location and height of the calibration points determine the transfer function.

According to an embodiment of the present invention, the plate bending measurement method further includes: selecting a measurement area from the measurement image according to the area to be measured on the object to be measured; N effective measurement points in the measurement area, where N≧3; according to the height of the object to be measured at the position corresponding to the N effective measurement points, an oblique/curved surface compensation image corresponding to the area to be measured is generated to compensate The deformation of the object to be measured in the area to be measured.

According to an embodiment of the present invention, the reference points include at least one first reference point and multiple second reference points. The pattern of the at least one first reference point is different from the pattern of the second reference point.

According to an embodiment of the present invention, the image includes multiple first lines and multiple second lines. The first line and the second line intersect each other to form the reference point.

Another aspect of the present invention is to provide a bending measuring device for measuring an object to be measured. The plate bending measurement device includes a measurement carrier, a projection module, an imaging module and a processing module. The measuring carrier is used to carry the object to be measured. The projection module is used for projecting an image on the object to be tested, wherein the image contains multiple reference points. The image capturing module is used for capturing a measurement image when the image is projected on the object to be measured, wherein the measurement image includes a plurality of measurement points corresponding to the reference points respectively. The processing module is used to calculate the position of each of the measurement points in the measurement image through the conversion function corresponding to each of the reference points to obtain the position of the object to be measured corresponding to the measurement point, and generate a plate bending compensation image corresponding to the object to be measured according to the height of the object to be measured at the position corresponding to the measurement point, so as to compensate the plate bending of the object to be measured.

According to an embodiment of the present invention, before measuring the object to be measured, the plate bending measuring device is used to determine the transfer function. The measuring carrier is used to carry the calibration plate. The projection module is used for projecting the image on the calibration plate. The image capturing module is used to capture multiple corrected images when the image is projected on the corrected plate when the image captured module has multiple corrected heights relative to the corrected plate, wherein the corrected images are Each of the calibration images includes a plurality of calibration points respectively corresponding to the reference points; the processing module is used to measure the height of each calibration point of the calibration points in the corresponding calibration image, and according to the calibration The transfer function is determined by the position and height of the calibration point corresponding to the same reference point in each calibration image in the images.

According to an embodiment of the present invention, the processing module is further configured to select a measurement area from the measurement image according to the area to be measured on the object to be measured, and to select from the measurement points adjacent to the N effective measurement points in the measurement area, wherein N≧3; generating a slope/curved surface compensation image corresponding to the area to be measured according to the height of the object to be measured at a position corresponding to the N effective measurement points, In order to compensate the deformation of the object to be measured in the area to be measured.

According to an embodiment of the present invention, the reference points include at least one first reference point and multiple second reference points. The pattern of the at least one first reference point is different from the pattern of the second reference point.

According to an embodiment of the present invention, the image includes multiple first lines and multiple second lines. The first line and the second line intersect each other to form the reference point.

One aspect of the present invention is to provide a method for measuring plate bending. The plate bending measurement method is used for measuring the object to be measured, wherein the object to be measured is placed on a measuring carrier. The plate bending measurement method includes: projecting an image on the object to be measured, wherein the image includes multiple reference points; capturing the measurement image when the image is projected on the object to be measured by the imaging module, wherein the measurement image includes multiple quantities The measuring points are respectively corresponding to the reference points; the position of each measuring point in the measuring point is passed through a lookup table (Lookup table) to obtain the position of the object to be measured at the position corresponding to the measuring point. height; and generating a plate bending compensation image corresponding to the object to be measured according to the height of the object to be measured at the position corresponding to the measuring point, so as to compensate the plate bending of the object to be measured.

According to an embodiment of the present invention, before measuring the object to be measured, the plate bending measurement method includes: projecting the image on a calibration plate placed on the measurement carrier; When the module has multiple calibration heights relative to the calibration plate, multiple calibration images when the image is projected on the calibration plate are captured by the imaging module, wherein each calibration image in the calibration images includes multiple calibration points Respectively corresponding to the reference points; measuring the height of each calibration point of the calibration points in the corresponding calibration image; and recording the calibration points corresponding to the same reference point in each calibration image of the calibration images The location and height to generate the lookup table (Lookup table).

To sum up, through the projection module, an image with a specific style and reference point is generated on the object to be measured, and according to the corresponding position of the measurement point in the measurement image captured by the imaging module and the reference point in the image, it can be Quickly judge whether the object to be tested has a plate bend, and quickly adjust the focal length position of the imaging module. Then, by means of a conversion function or a lookup table, the height of the object to be measured can be quickly obtained, and the plate bending of the object to be measured can be compensated to generate a compensation image. On the other hand, through the deformation measuring method of the present invention, the local inclination or bending of the object to be measured can be further judged, and accurately corrected and compensated.

Description of drawings

In order to make the above and other objects, features, advantages and embodiments of the present invention more comprehensible, the accompanying drawings are described as follows:

Fig. 1 is a flow chart of a method for measuring plate bending according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of a plate bending measuring device that can be used in conjunction with the plate bending measuring method in an embodiment of the present invention;

FIG. 3A is a schematic diagram of an image generated by a projection module according to an embodiment of the present invention;

3B is a schematic diagram of a measurement image captured by the imaging module according to an embodiment of the present invention;

FIG. 3C is a schematic diagram of another measurement image captured by the imaging module according to an embodiment of the present invention;

FIG. 3D is a schematic diagram of another measurement image captured by the imaging module according to an embodiment of the present invention;

FIG. 4A is a schematic diagram of another image generated by the projection module according to an embodiment of the present invention;

Fig. 4B is a schematic diagram of another image generated by the projection module according to an embodiment of the present invention;

FIG. 4C is a schematic diagram of another image generated by the projection module according to an embodiment of the present invention;

5A is a schematic diagram of another plate bending measuring device that can be used in conjunction with the plate bending measuring method according to an embodiment of the present invention;

5B is a schematic diagram of another plate bending measuring device that can be used in conjunction with the plate bending measuring method according to an embodiment of the present invention;

FIG. 6 is a flowchart of a conversion function generation method according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of corrected images captured by the imaging module at different corrected heights according to an embodiment of the present invention;

FIG. 8A is a schematic diagram of a corrected image at a corrected height according to an embodiment of the present invention;

FIG. 8B is a schematic diagram of a corrected image at another corrected height according to an embodiment of the present invention;

FIG. 8C is a schematic diagram of a corrected image at another corrected height according to an embodiment of the present invention;

Fig. 9 is a flow chart of a deformation measurement method according to an embodiment of the present invention;

FIG. 10A is a schematic diagram of a measurement area in a measurement image according to an embodiment of the present invention;

FIG. 10B is a schematic diagram of another measurement area in a measurement image according to an embodiment of the present invention; and

FIG. 10C is a schematic diagram of compensation through the deformation measurement method in FIG. 9 according to an embodiment of the present invention.

detailed description

The following examples are described in detail in conjunction with the accompanying drawings, but the provided examples are not used to limit the scope of the present invention, and the description of the structural control is not used to limit the order of its execution. Any recombination of components Structures, resulting devices with equivalent functions are all within the scope of the present invention. In addition, the drawings are for illustrative purposes only and are not drawn to scale. For ease of understanding, the same components will be described with the same symbols in the following description.

As used herein, "about", "approximately" or "approximately" generally means that the error or range of the value is within 20%, preferably within 10%, and preferably within Within five percent. If there is no explicit statement in the text, the numerical values mentioned are all regarded as approximate values, such as errors or ranges that can be expressed as "about", "approximately" or "approximately", or other approximate values.

It is understandable that terms such as first, second and third are used herein to describe various elements, components, regions, layers and/or blocks. But these elements, components, regions, layers and/or blocks should not be limited by these terms. These terms are limited to identifying a single element, component, region, layer and/or block. Therefore, a first element, component, region, layer and/or block hereinafter may also be referred to as a second element, component, region, layer and/or block without departing from the spirit of the present invention.

A number of implementations of the present invention will be disclosed below with the accompanying drawings. For the sake of clarity, many specific details will be described together in the following description. It should be understood, however, that these specific details should not be used to limit the invention. That is, in some embodiments of the invention, these specific details are not necessary. In addition, for the sake of simplifying the drawings, some well-known and commonly used structures and elements will be described in a simple and schematic manner in the drawings.

Please refer to FIG. 1 and FIG. 2 . FIG. 1 is a flow chart of a method 100 for measuring plate bending according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a plate bending measuring device 200 that can be used in conjunction with the plate bending measuring method 100 according to an embodiment of the present invention, but the plate bending measuring device 200 in FIG. 2 is only an illustration, The panel bending measurement method 100 of the present invention is not limited to the hardware structure of the panel bending measurement device 200 shown in FIG. 2 .

As shown in FIG. 2 , the plate bending measurement device 200 includes a measurement carrier 210 , a projection module 220 , an image capturing module 230 and a processing module 240 . The measurement carrier 210 may include a carrier platform 211 and a mobile unit 212 . The carrier platform 211 is used to carry the object 250 to be tested. The moving unit 212 is used to drive the carrier platform 211 to move vertically. In this way, the carrier platform 211 can drive the object to be measured 250 to move vertically, but this embodiment is not limited thereto. In another embodiment, the position of the imaging module 230 can also be moved vertically so that it can move vertically relative to the object 250 to be measured, so as to change the vertical height to the object 250 to be measured. The projection module 220 is disposed above the measurement carrier 210 and faces the object to be measured 250 in a direction or an angle. The image capturing module 230 is disposed directly above the measurement carrier 210 .

In one embodiment, the object 250 to be measured by the bending measuring device 200 may include a circuit board, an optical plate or other substrates.

In this embodiment, the projection module 220 can be a digital projection device for generating images with special styles. Please also refer to FIG. 3A , which is a schematic diagram of an image 300A generated by the projection module 220 according to an embodiment of the present invention. The image 300A may include a plurality of reference points RP1 - RP9 . For the convenience of description, the reference points RP1 - RP9 are evenly distributed on the image 300A, and the shapes and sizes are substantially the same, but this embodiment is not limited thereto. It should be noted that the image 300A in FIG. 3A is only illustrative. In other words, the shape and size of the image 300A, the number of reference points included in it, and the positions of the reference points can be changed according to actual needs, and the present invention does not This is not the limit.

As shown in FIG. 1 , in the plate bending measurement method 100 , first, in step S110 , an image with a specific pattern (for example: image 300A) is projected on the object 250 to be measured by the projection module 220 . Next, in step S130 , the measurement image when the image 300A is projected on the object 250 to be measured is captured by the image capturing module 230 . Since the measurement image is an image of the image 300A projected on the object 250 to be measured, the measurement image also includes the number of measurement points corresponding to the reference points RP-RP9.

Please refer to FIG. 3B and FIG. 3C together. FIG. 3B is a schematic diagram of a measurement image 300B captured by the image capturing module 230 according to an embodiment of the present invention, and FIG. 3C is another measurement image captured by the image capturing module 230 according to an embodiment of the present invention. Schematic of Image 300C. Specifically, if the object 250 to be measured does not have any bending, the measurement image captured by the imaging module 230 should be the measurement image 300B shown in FIG. 3B . In other words, the measurement points MP1 - MP9 in the measurement image 300B are evenly distributed on the measurement image 300B like the reference points RP1 - RP9 of the image 300 .

However, if the object to be measured 250 has a plate bend, as shown in FIG. 2 , the measurement point in the measurement image captured by the imaging module 230 will be offset corresponding to the protruding part of the object to be measured 250 Case. In other words, the measurement image captured by the image capturing module 230 is similar to the measurement image 300C shown in FIG. 3C . In FIG. 3C , the measurement image 300C also includes measurement points MP1 ′˜MP9 ′ corresponding to the number of reference points RP˜RP9 . However, the measurement points MP4 ′˜MP6 ′ have deviated from their original positions. In other words, the position of the object 250 to be measured relative to the measurement points MP4 ′˜MP6 ′ may be bent.

Further, as the height of the object 250 to be measured is different, the positions of the measurement points in the measurement image captured by the imaging module 230 (for example: the measurement image 300C) will also be different. Therefore, the height of the object to be measured 250 relative to each measurement point can be known by calculating the offset of each measurement point (eg, measurement points MP1 ′˜MP9 ′).

Therefore, in step S150, the processing module 240 can further compare the positions of the measurement points (for example: measurement points MP1'˜MP9') in the measurement image (for example: measurement image 300C) by corresponding to the reference point RP1 The conversion functions of ˜RP9 are calculated to obtain the height of the object 250 to be measured at the position corresponding to the measurement point (for example: measurement points MP1 ′˜MP9 ′). Specifically, the processing module 240 can convert the coordinates of the measurement points (for example, the measurement points MP1 ′˜MP9 ′) in the measurement image (for example, the measurement image 300C) into heights through corresponding conversion functions.

Next, in step S170 , a plate bending compensation image is generated according to the height of the object to be measured 250 at the position corresponding to the measurement point, so as to compensate the plate bending of the object to be measured 250 . Specifically, if the heights of the positions corresponding to the measurement points of the object to be measured 250 are similar, it means that the object to be measured 250 does not have a plate bend, so the image capturing module 230 captures the height of the object to be measured 250 at this time. The image is the correct image without further compensation. Relatively, if the height of the positions corresponding to some of the measuring points (for example: measuring points MP4'˜MP6’) of the object to be measured 250 is different from the heights of other measuring points, it means that the object to be measured 250 may have a plate In the case of a bend, the image of the object under test 250 captured by the image capturing module 230 is an incorrect image. Since the actual height of the object to be measured 250 at the corresponding measurement point can be quickly obtained through the conversion function, the processing module 240 can quickly compensate for the height difference to obtain a correct image of the object to be measured 250 .

In this embodiment, the reference points RP1 - RP9 included in the image 300A have substantially the same shape and size, and are evenly distributed in the image 300A. However, when the offset of the measurement point corresponding to the reference point is too large, it may cause the processing module 240 to make a misjudgment. For example, please refer to FIG. 3D , which is a schematic diagram of another measurement image 300D captured by the imaging module 230 according to an embodiment of the present invention. In this embodiment, due to the large offset, the image capturing module 230 cannot capture the measurement points MP1 - MP3 corresponding to the reference points RP1 - RP3 . On the other hand, the processing module 240 cannot determine whether the measurement point MP4 corresponds to the reference point RP1 or RP4 of the image 300A. In this embodiment, the processing module 240 may misjudge the measurement points MP1 - MP3 as corresponding reference points RP1 - RP3 . In such a case, the processing module 240 may cause problems in the height compensation based on the position of the object to be measured 250 corresponding to the measurement point.

Please refer to FIG. 4A , which is a schematic diagram of another image 400A generated by the projection module 220 according to an embodiment of the present invention. As shown in FIG. 4A , an image 400A includes reference points RP1 - RP16 . In this embodiment, the reference points RP1-RP16 are not evenly distributed on the image 400A, and the reference points RP1-RP16 include multiple reference points (for example: reference points RP2, RP8, RP10, RP11 and RP13) and other The styles (for example: shape, size, color, etc.) of the reference points (for example: reference points RP1, RP3-RP7, RP9 and RP12) are different. The style may include shape, size, color, etc. In this embodiment, different shapes are used as an example, but the present invention is not limited thereto. In this way, when the position of the measurement point in the measurement image captured by the imaging module 230 is different from the reference point of the image 400A, the processing module 240 can judge according to the measurement points corresponding to different styles of reference points Which reference points the measurement points correspond to, and avoid misjudgment. Then, the processing module 240 compensates for the plate bending of the object 250 to be measured according to the offset of the measuring point corresponding to the correct reference point.

Please refer to FIG. 4B , which is a schematic diagram of another image 400B generated by the projection module 220 according to an embodiment of the present invention. As shown in FIG. 4B , the reference points RP1 - RP16 included in the image 400B are evenly distributed in the image 400B, and the shapes, sizes, and colors are approximately the same. However, the difference from the image 300A in FIG. 3 is that the image 400B also includes a straight line 410 between the reference points RP5 - RP8 and the reference points RP9 - RP12 . In this way, the processing module 240 can determine which reference points the measurement points in the measurement image correspond to according to the straight lines in the measurement image. It should be noted that the image 400B in this embodiment is an example of a straight line, but the present invention is not limited thereto.

Please refer to FIG. 4C , which is a schematic diagram of another image 400C generated by the projection module 220 according to an embodiment of the present invention. As shown in FIG. 4C , unlike images 300A, 400A, and 400B, image 400C includes a plurality of lines 420 - 470 . In this embodiment, the lines 420-470 are straight lines as an example, but the present invention is not limited thereto. The interval distance of each line is different. The lines 420 , 430 and 440 are different in thickness from the lines 450 , 460 and 470 , and are interlaced with each other to form reference points RP1 - RP9 . In this way, the processing module 240 can determine which reference points the measurement points in the measurement image correspond to according to the lines 420 - 470 in the corresponding measurement image.

It should be noted that the above image embodiments are only examples, but they are not intended to limit the content of the disclosure; in other words, any person skilled in the art can make various Different options and modifications.

It is worth mentioning that the image is generated by the projection module 220 in the bending measurement method 100 proposed by the present invention. The projection module 220 can be a projection device such as a digital projector, so it is easy to generate and replace images. When the processing module 240 cannot make a judgment based on the measurement image generated by a certain image, the user can use the projection module 220 to generate another set of images (eg, images with more reference points) for measurement at any time. Due to the traditional plate bending measurement method, the light-projecting instrument needs to include a grating, and different gratings need to be replaced according to the object to be measured and the measurement method. The complexity and cost of the operation are very high. Therefore, the method proposed by the present invention is more convenient and flexible in operation.

Please refer to FIG. 5A. FIG. 5A is a schematic diagram of another plate bending measuring device 500A that can be used in conjunction with the plate bending measuring method 100 according to an embodiment of the present invention, but the plate bending measuring method 100 of the present invention does not It is not limited to the hardware structure of the plate bending measuring device 500A shown in FIG. 5A . As shown in FIG. 5A, similar to the plate bending measuring device 200 in FIG. , whose operation is similar to that of the measurement carrier 210 , the projection module 220 , the imaging module 230 and the processing module 240 in FIG. 2 , which are not described here.

In this embodiment, the plate bending measurement device 500 includes a plurality of projection modules 521 and 522 and a plurality of imaging modules 531 and 532 . For the convenience of description, the number of projection modules and imaging modules in this embodiment is two, but the present invention is not limited thereto. In FIG. 2, since the projection module 210 is biased toward a specific direction of the object to be measured 250, when the projection module 210 projects an image on the object to be measured 250, it is possible that the imaging module 230 may obtain The measured image has shadows.

However, in this embodiment, the projection modules 521 and 522 are disposed above the measurement carrier 510 , and the projection module 522 is disposed at a position different from the projection module 521 . In other words, the projection module 522 can project an image onto the object 250 to be measured in a direction different from that of the projection module 521 . The image capturing module 531 can be used to capture the image projected by the projection module 521 on the object 250 to be measured, and the image capturing module 532 can be used to capture the image projected by the projection module 522 on the object 250 to be measured. In this way, the occurrence of shadows caused by imaging by a single imaging module can be avoided. In addition, the processing module 540 can also distribute and process the measurement images captured by the image capturing modules 531 and 532 to speed up the speed of determining the bending condition of the board.

Please refer to FIG. 5B. FIG. 5B is a schematic diagram of another plate bending measuring device 500B that can be used in conjunction with the plate bending measuring method 100 according to an embodiment of the present invention, but the plate bending measuring method 100 of the present invention does not It is not limited to the hardware structure of the bending measuring device 500B in FIG. 5B . As shown in FIG. 5B , the operation of the bending measuring device 500B is similar to that of the bending measuring device 500A shown in FIG. 5A , which is not described here.

In this embodiment, the projection modules 521 and 522 are disposed directly above the measurement carrier. The imaging modules 531 and 532 are disposed on the measurement carrier and face the object 250 to be measured in different directions. In other words, compared with the plate bending measuring device 500A, the positions of the projection modules 521 and 52 and the image capturing modules 531 and 532 are reversed. In other words, the bending measuring device applied to the bending measuring method 100 of the present invention can determine the positions of the projection module and the imaging module according to actual needs, and the present invention is not limited thereto.

Please refer to FIG. 6 , which is a flowchart of a method 600 for generating a conversion function according to an embodiment of the present invention. Specifically, the conversion function generation method 600 is to pre-establish the conversion function of each reference point before measuring the object to be measured 250, so that when the object to be measured 250 is measured, after knowing the measurement point of the measurement image , the height of the object to be measured 250 at the position corresponding to the measurement point can be quickly obtained.

The conversion function generation method 600 can be used with the plate bending measurement device 200 of FIG. 2 , the plate bending measurement device 500A of FIG. 5A or the plate bending measurement device 500B of FIG. 5B , and the image 300A of FIG. Image 400B of FIG. 4B or image 400C of FIG. 4C. In this embodiment, the transfer function generation method 600 is exemplified by the bending measurement device 200 in FIG. 2 and the image 300A in FIG. 3A , but the invention is not limited thereto.

First, in step S610 , the calibration plate is placed on the carrier platform 211 . Next, in step S630 , the projection module 220 projects an image with a specific pattern (for example: image 300A) on the calibration plate. Next, change the distance between the carrier platform 211 and the imaging module 230 (for example: by driving the mobile unit 212 or moving the imaging module 230), so that when the imaging module 230 has multiple corrected heights relative to the carrier platform 211, by The image capturing module 230 captures a plurality of calibration images when the image 300 is projected on the calibration plate. Likewise, each calibration image includes a plurality of calibration points respectively corresponding to the reference points RP1 - RP9 of the image 300A.

Next, in step S650 , the height of each calibration point at the position of the corresponding calibration image is measured, and the position and height of each calibration point at the corresponding calibration image are recorded. In one embodiment, the height of each calibration point at the position of the corresponding calibration image can be measured by a triangulation method. Next, in step S670, a conversion function corresponding to the reference point is obtained according to the position and height of the calibration point corresponding to the same reference point in each calibration image.

Please refer to FIG. 7 , FIG. 8A , FIG. 8B and FIG. 8C together. FIG. 7 is a schematic diagram of calibration images captured by the imaging module 230 at different calibration heights according to an embodiment of the present invention. FIG. 8A is a schematic diagram of a calibration image 800A captured at a calibration height HC1 according to an embodiment of the present invention, and FIG. 8B is a calibration image 800B captured at another calibration height HC2 according to an embodiment of the present invention. 8C is a schematic diagram of a calibration image 800C captured at another calibration height HC3 according to an embodiment of the present invention. As shown in FIG. 7 , the user can project an image with a specific pattern (for example, the image 300A) on the calibration plate 710 through the projection module 220 . Next, the user can drive the moving unit 212 or move the imaging module 230 so that the imaging module 230 has a plurality of calibration heights HC1 - HC3 relative to the calibration plate 710 . And the calibration images 800A- 800C of the calibration plate 710 at the calibration heights HC1 - HC3 are respectively captured by the image capture module 230 . Similarly, under normal circumstances, the corrected image 800A may include corrected points CP1 - CP9 corresponding to the number of reference points (eg, reference points RP - RP9 ) of the image (eg, image 300A ). The corrected image 800B may include corrected points CP1 ′˜CP9 ′ corresponding to the number of reference points (eg, reference points RP˜RP9 ) of the image (eg, image 300A ). The corrected image 800C may include corrected points CP1 ″˜CP9 ″ corresponding to the number of reference points (eg, reference points RP˜ RP9 ) of the corresponding image (eg, image 300A ).

Since the angle projected by the projection module 220 is unchanged, when the calibration height is different, the calibration points in the calibration image will be shifted. As shown in Figure 8A, Figure 8B and Figure 8C. When the distance between the calibration plate 710 and the imaging module 230 moves from the calibration height HC1 to the calibration height HC3, the positions of the calibration points CP1 ″-CP9 ″ of the calibration image 600C are opposite to the positions of the calibration points CP1 ′-CP9 ′ of the calibration image 600B. The positions of the calibration points CP1 - CP9 in the calibration image 600A have all changed.

In addition, the position (for example: coordinates) of the calibration point of each calibration image can be recorded by the processing module 240, and the height of the calibration point can also be measured by triangulation. Therefore, through the position and height of the calibration point corresponding to the same reference point in each calibration image, the relationship between the position and height of the calibration point, that is, the conversion function corresponding to the reference point can be obtained.

In one embodiment, the location information of the reference point is obtained according to different heights, and a conversion function is obtained by using a regression method. The form of the conversion function may be polynomial of degree one or higher, trigonometric function, exponential function, etc., and the present invention is not limited thereto. Furthermore, the style of the conversion function is determined according to the position and height of each calibration point corresponding to the same reference point and the error range. When the complexity of the position and height of the calibration point is higher, and you want The smaller the error of the measurement result is, the higher the order of the transfer function may be. In this way, the relationship between the position and height of each calibration point corresponding to the same reference point can be solved.

For example, suppose the transfer function is h(x,y)=ax+by, where h(x,y) is the height of the calibration point, and (x,y) is the coordinate of the calibration point. The coordinates of the calibration point CP1 corresponding to the reference point RP1 in the calibration image 800A are (3,-3), and the height of the calibration point CP1 is 300 millimeters (mm); the coordinates of the calibration point CP1' corresponding to the reference point RP1 in the calibration image 800B are Labeled (2.5,-4), the height of the calibration point CP1' is 350 millimeters (mm). Substituting the above available variables into the above formula to solve the simultaneous equations, the transfer function corresponding to the reference point RP1 can be obtained as h(x, y)=100/3*x−200/3*y. In this way, when the object 250 to be measured is measured by the plate bending measurement method 100, the coordinates of the measurement point corresponding to the reference point RP1 in the measurement image can be substituted into its corresponding conversion function h(x,y) =100/3*x−200/3*y, the height corresponding to the measuring point of the object 250 to be measured can be quickly obtained.

However, for the calibration image 800C, if the coordinates of the calibration point CP1 ″ corresponding to the reference point RP1 are (2, −5), the height of the calibration point CP1 ″ is 380 mm. However, through the above conversion function h(x,y)=100/3*x-200/3*y, the height of the correction point ideally corresponding to the reference point RP1 is 400 mm, which is exactly the same as the measured actual height of 380 mm. 20 mm error, at this time, it may be necessary to assume that the conversion function is a higher-order polynomial or other functions (such as: trigonometric or exponential functions, etc.) to solve each calibration image (such as: calibration image 800A, 800B and 800C), the relationship between the positions and heights of the calibration points CP1, CP1' and CP1" corresponding to the reference point RP1.

Therefore, through the conversion function generation method 600, a conversion function corresponding to each reference point (for example: reference points RP1-RP9) in the image (for example: image 300A) can be obtained. Therefore, when the object 250 to be measured is measured by the plate bending measurement method 100, the position of each measurement point in the captured measurement image can be calculated through the conversion function of its corresponding reference point, thereby The height of the position of the measurement point corresponding to the object 250 to be measured is quickly obtained. In one embodiment, the area of the image projected by the projection module 220 can be greater than or equal to the area of the object to be measured 250, so the overall approximate height of the object to be measured 250 can be quickly obtained, that is, it can be quickly judged whether the object to be measured 250 has The board is bent, and the focal length position of the imaging module 230 is quickly adjusted. If the object 250 to be tested is bent, the processing module 240 can quickly make height compensation according to the obtained height difference.

It is worth mentioning that, in the present invention, the bending measurement method 100 obtains the height of the object to be measured 250 at the position corresponding to the measurement point through a conversion function. However, in another embodiment, the user can also use a lookup table to obtain the height of the object 250 to be measured at the position corresponding to the measurement point. Specifically, before measuring the object to be measured, a plurality of calibration images corresponding to a certain image can be obtained by performing calibration and compensation on the calibration plate. Then, record the position and height of each calibration point in the corresponding calibration image in a lookup table. In this way, when measuring the object to be measured, after the measurement image is obtained, the processing module can query the position of the measurement point through the lookup table and quickly obtain the corresponding height, and then judge the height of the object to be measured Plate bending and compensation. In other words, the bending measurement method 100 of the present invention is not limited to obtaining the height of the object to be measured by the transfer function.

It should be noted that, in actual situations, the object 250 to be tested is a circuit board, an optical plate or other substrates, on which solder paste is soldered. Since the height of the solder paste is very small compared to the height of the substrate, the error generated by the board warp measurement method 100 will not have a great impact on the board warp compensation. Since the plate bending measurement method 100 can obtain the height of the object to be measured at one time, compared with the traditional method of moving the projection device sequentially to measure the object to be measured, its efficiency and scanning time can be effectively improved.

In one embodiment, the plate bending measuring device 200 in FIG. 2 can also be used to measure and compensate the deformation of the area to be tested in the object to be tested 250 . Please refer to Figure 9. FIG. 9 is a flowchart of a deformation measurement method 900 according to an embodiment of the present invention. For convenience of description, the deformation measurement method 900 takes the plate bending measurement device 200 in FIG. 2 and the image 300A in FIG. 3A as examples, but the present invention is not limited thereto.

As shown in FIG. 9 , first, in step S910 , the processing module 240 may select a measurement area from the measurement image according to the area to be measured on the object to be measured 250 . In other words, the measurement area is the position and range corresponding to the area to be measured in the measurement image. Specifically, the user can select the area to be measured according to the deformation of a certain part of the object 250 to be measured. The processing module 240 can find out the measurement area corresponding to the area to be measured in the measurement image according to the area to be measured selected by the user.

Next, in step S930 , the processing module 240 may select N effective measurement points adjacent to the measurement area from all measurement points in the measurement image, where N≧3. Specifically, as long as there are three points, a plane can be determined. Therefore, it is only necessary to select three measurement points near the adjacent measurement area to determine whether the measurement area has an inclination (that is, a slope is generated). On the other hand, if the number of selected measurement points is larger, it can be further judged whether there is a curvature in the measurement area (that is, a curved surface is generated). In other words, those skilled in the art can select the number of measurement points according to actual needs, and the present invention is not limited thereto.

Next, in step S950, an oblique/curved surface compensation image corresponding to the area to be measured is generated according to the height of the object to be measured 250 corresponding to the positions of the N effective measurement points, so as to compensate the deformation of the object to be measured 250 in the area to be measured Condition. Specifically, if the object to be measured 250 is not deformed in the region to be measured, the positions of the N valid measurement points in the measurement image should be the same as the positions of the reference points in the corresponding image. However, if the object to be measured 250 is deformed on the region to be measured, the positions of some of the N effective measurement points should deviate from the positions of the corresponding reference points of the image. Therefore, the processing module 240 can generate oblique/curved surface compensation images according to the offsets of the N effective measurement points, so as to compensate the deformation of the object 250 to be measured in the region to be measured.

Specifically, the processing module 240 can calculate the N effective measurement points through the conversion function of the corresponding reference point to obtain the height of the object to be measured at the position corresponding to the N effective measurement points, and judge according to the height difference The amount of inclination or curvature of the object to be measured in the area to be measured, and then generate an oblique/curved surface compensation image according to the amount of inclination or curvature.

Please refer to FIG. 10A , FIG. 10B and FIG. 10C together. FIG. 10A is a schematic diagram of a measurement area 1000A in a measurement image according to an embodiment of the present invention. FIG. 10B is a schematic diagram of another measurement area 1000B in a measurement image according to an embodiment of the present invention. FIG. 10C is a schematic diagram of compensation through the deformation measurement method 900 in FIG. 9 according to an embodiment of the present invention.

Specifically, if the object to be measured does not bend or tilt locally (that is, the area to be measured corresponding to the measurement area), as shown in FIG. 10A , the measurement in the measurement image obtained by the imaging module In the area 1000A, the positions of the measurement points are not shifted relative to the reference point, and the components 1100 (eg, pads (PAD)) in the measurement area 1000A are not deformed. However, if the object to be measured is partially bent or inclined, as shown in FIG. 10B , the measurement area 1000B in the measurement image obtained by the imaging module has already generated the position of the measurement point relative to the reference point. deviation, and the element 1100 in the measurement area 1000V is also deformed. In such a case, through the deformation measurement method 900 of the present invention, the deformation of the measurement point adjacent to the measurement area can be judged according to the offset, and then the measurement point is corrected to correspond to the reference point position, so as to compensate the deformation of the component 1100 and generate a compensated image.

It can be understood that if the number of measurement points adjacent to the measurement area is selected to be more, the degree of deformation of the object to be measured can be estimated more accurately, and the accuracy of the oblique/curved surface compensation image will be higher.

It is worth mentioning that if a specific image cannot effectively measure the whole of the object to be measured, the user can choose another image of another style to replace it. Compared with the traditional As far as the grating is concerned, the required cost can also be effectively reduced. For example, if the measurement image captured by the imaging module 230 when the image 300A is projected on the object to be measured lacks the measurement points corresponding to the reference point RP1, the user can replace other images (for example: an image with 16 reference points ) is projected on the object to be measured, and then a measurement image of the image projected on the object to be measured is captured to compensate for plate bending of the object to be measured.

In summary, the bending measurement method proposed by the present invention uses a projection module (such as a digital projection device) to generate an image with a specific pattern and reference points on the object to be measured, and according to the measurement captured by the imaging module The corresponding position of the measurement point in the image and the reference point in the image can quickly determine whether the object to be measured has a plate bend, and can quickly adjust the focal length position of the imaging module. Then, by means of a conversion function or a lookup table, the height of the object to be measured can be quickly obtained, and the height compensation of the plate bending of the object to be measured can be performed. On the other hand, through the deformation measuring method of the present invention, the local inclination or bending of the object to be measured can be further judged, and accurately corrected and compensated.

Although the present invention has been disclosed as above in terms of implementation, it is not intended to limit the present invention. Any person skilled in the art can make various choices and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection is defined by the claims and their equivalents.

Claims (12)

1. the curved method for measurement of plate, is used for measuring object under test, it is characterised in that described object under test is placed in measurement carrier On, the curved method for measurement of described plate comprises:

Being incident upon by image on described object under test, wherein said image comprises multiple reference point；

Measurement image when described image is projeced into described object under test, wherein said measurement image bag is captured by image extraction module Containing multiple measuring points corresponding the plurality of reference point respectively；

By each measuring point in the plurality of measuring point in the position of described measurement image by corresponding the plurality of reference point In each reference point transfer function calculate to obtain the described object under test height in the position of corresponding the plurality of measuring point Degree；And

The plate of corresponding described object under test is produced according to the described object under test height in the position of corresponding the plurality of measuring point Curved compensation image, so as to compensating the curved situation of plate of described object under test.

2. the curved method for measurement of plate as claimed in claim 1, it is characterised in that before measuring described object under test, comprise:

Described image is incident upon the correcting plate being placed on described measurement carrier；

When described image extraction module has multiple calibrated altitude relative to described correcting plate, captured described by described image extraction module Image is projeced into multiple correcting images during described correcting plate, and each correcting image in wherein said multiple correcting images comprises Multiple check points corresponding the plurality of reference point respectively；

Measure each check point of the plurality of check point height in corresponding the plurality of correcting image；And

The position of the check point according to same reference point corresponding in each correcting image in the plurality of correcting image and height Degree determines described transfer function.

3. the curved method for measurement of plate as claimed in claim 1, it is characterised in that the curved method for measurement of described plate also comprises:

Measurement region is chosen from described measurement image according to the region to be measured on described object under test；

N number of effective dose measuring point in neighbouring described measurement region, wherein N 3 are chosen from the plurality of measuring point；And

Corresponding described region to be measured is produced according to the described object under test height in the position of corresponding described N number of effective dose measuring point Tiltedly/curved surface compensates image, so as to compensating the deformation situation in described region to be measured of described object under test.

4. the curved method for measurement of plate as claimed in claim 1, it is characterised in that the plurality of reference point comprise at least one the The sample of one reference point and multiple second reference point, the pattern of at least one the first reference point described and the plurality of second reference point Formula is different.

5. the curved method for measurement of plate as claimed in claim 1, it is characterised in that described image comprises a plurality of First Line, a plurality of Second line, described a plurality of First Line and the described a plurality of second line the plurality of reference point of formation interlaced with each other.

6. the curved measuring equipment of plate, is used for measuring object under test, it is characterised in that the curved measuring equipment of described plate comprises:

Measuring carrier, it is used for carrying described object under test；

Projection module, it comprises multiple reference point for projects images at described object under test, wherein said image；

Image extraction module, it is for capturing measurement image when described image is projeced into described object under test, wherein said measurement shadow As comprising multiple measuring point corresponding the plurality of reference point respectively；And

Processing module, it is described by correspondence in the position of described measurement image by each measuring point in the plurality of measuring point The transfer function of each reference point in multiple reference points calculates to obtain the described object under test position at corresponding described measuring point The height put, and produce plate curved compensation image according to the described object under test height in the position of corresponding the plurality of measuring point, So as to compensating the curved situation of plate of described object under test.

7. the curved measuring equipment of plate as claimed in claim 6, it is characterised in that before measuring described object under test, described The curved measuring equipment of plate is used for determining that described transfer function, described measurement carrier are used for carrying correcting plate；Described projection module is used for Described image is incident upon on described correcting plate；Described image extraction module is for having relative to described correcting plate at described image extraction module When having multiple calibrated altitude, capture multiple correcting images when described image is projeced into described correcting plate, wherein said multiple schools Each correcting image in positive image comprises multiple check point corresponding the plurality of reference point respectively；The described processing module amount of being used for Survey each check point of the plurality of check point height in corresponding the plurality of correcting image, and according to the plurality of school The position of the check point of corresponding same reference point and highly determine described transfer function in each correcting image in positive image.

8. the curved measuring equipment of plate as claimed in claim 6, it is characterised in that described processing module is additionally operable to according to described Measurement region is chosen from described measurement image in region to be measured on object under test, and chooses neighbouring institute from the plurality of measuring point State the N number of effective dose measuring point measuring region, wherein N 3, and according to described object under test in corresponding described N number of effective measurement The height of the position of point produces the oblique/curved surface in corresponding described region to be measured and compensates image, so as to compensate described object under test in institute State the deformation situation in region to be measured.

9. the curved measuring equipment of plate as claimed in claim 6, it is characterised in that the plurality of reference point comprise at least one the The sample of one reference point and multiple second reference point, the pattern of at least one the first reference point described and the plurality of second reference point Formula is different.

10. the curved measuring equipment of plate as claimed in claim 6, it is characterised in that described image comprises a plurality of First Line, a plurality of Second line, described a plurality of First Line and the described a plurality of second line the plurality of reference point of formation interlaced with each other.

11. 1 kinds of curved method for measurement of plate, are used for measuring object under test, it is characterised in that described object under test is placed in measurement and carries On tool, the curved method for measurement of described plate comprises:

Being incident upon by image on described object under test, wherein said image comprises multiple reference point；

Measurement image when described image is projeced into described object under test, wherein said measurement image bag is captured by image extraction module Containing multiple measuring points corresponding the plurality of reference point respectively；

Each measuring point in the plurality of measuring point is treated by look-up table in the position of described measurement image described in obtaining Survey the object height in the position of corresponding the plurality of measuring point；And

The plate of corresponding described object under test is produced according to the described object under test height in the position of corresponding the plurality of measuring point Curved compensation image, so as to compensating the curved situation of plate of described object under test.

12. a kind of curved method for measurement of plate as claimed in claim 11, it is characterised in that before measuring described object under test, Comprise:

Described image is incident upon the correcting plate being placed on described measurement carrier；

When described image extraction module has multiple calibrated altitude relative to described correcting plate, captured described by described image extraction module Image is projeced into multiple correcting images during described correcting plate, and each correcting image in wherein said multiple correcting images comprises Multiple check points corresponding the plurality of reference point respectively；

Measure each check point of the plurality of check point height in corresponding the plurality of correcting image；And

Record position and the height of the check point of corresponding same reference point in each correcting image in the plurality of correcting image Degree is to produce described look-up table.