JP2005093623A - Method and apparatus for recognizing substrate mark - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly recognize a substrate marks, even if the substrate mark sticks out of a detection frame due to variations in the dimensional precision of a substrate and positions, when transferring the substrate. <P>SOLUTION: Image data positioned in the detection frame 31 are subjected to arithmetic processings, to recognize whether the substrate mark 20a sticks out of the detection frame 31, and the detection frame 31 is enlarged toward the sticking-out direction, when the substrate mark 20a sticks out of the detection frame 31. Then, image data positioned in the enlarged detection frame are subjected to arithmetic processings, and the center-of-gravity position of the substrate mark 20a is transmitted to a main control unit 28, if the substrate mark 20a does not stick out of the enlarged detection frame. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a substrate mark recognition method and apparatus for recognizing the position of a substrate mark from an image obtained by imaging a substrate mark provided on a substrate.

In the electronic component manufacturing field, a method of applying image recognition is widely used as a method for accurately positioning an electronic component or a substrate. In this method, the position of a substrate mark, an electrode of an electronic component, an edge portion, or the like is detected by recognizing an image obtained by imaging the substrate or the electronic component.

In the detection of the position of the substrate mark by this image recognition, the CCD camera is moved above the substrate mark to perform imaging. At this time, it is necessary to set a target position for moving the CCD camera in advance. Conventionally, by aligning the center of the imaging field of the CCD camera with the substrate mark in the image obtained by imaging the substrate mark of the substrate set at the normal position, the position of the substrate mark is obtained and taught as the imaging reference position However, the CCD camera is moved with the taught position as a target.

By the way, in order to perform recognition, a detection frame is set in an imaged screen and an image processing range is limited to shorten the time required for recognition. By the way, the substrate mark may protrude from the detection frame due to variations in the dimensional accuracy of the substrate and the position of the substrate during transportation. In this case, accurate image recognition is not performed and the substrate cannot be positioned. Therefore, there is a method in which two large and small detection frames, that is, search areas are set in advance, pattern matching is first performed within the small search area, and if the matching rate is equal to or less than a set threshold value, the search area is expanded to a large search area (for example, Patent Literature 1).
Japanese Patent Laid-Open No. 10-261898

  However, the substrate mark is displaced so that it jumps out of the detection frame when there is a problem with the substrate transfer device. The deviation caused by the dimensional accuracy of the substrate and the variation in position during substrate transfer is It is a deviation that protrudes from the detection frame, that is, the substrate mark is placed on the upper, lower, left and right sides of the detection frame. When recognition is not possible with a small detection frame, recognizing using a large enlarged detection frame prepared in advance has a problem that it takes time for recognition.

  Therefore, in the present invention, when the substrate mark cannot be recognized with the default (initial setting) detection frame, the detection frame enlarged to the minimum necessary can be set and the substrate mark can be recognized in a short time. It is an object of the present invention to provide a substrate mark recognition method and apparatus for a substrate that can reduce the occurrence of recognition errors.

According to the first aspect of the present invention, there is provided a substrate mark recognition method for an electronic component mounting machine for recognizing a substrate mark for positioning on a substrate by imaging a substrate on which the electronic component is mounted with an imaging device. Detecting frame, recognizing a substrate mark in the detection frame, recognizing whether or not the substrate mark protrudes from the detection frame for each side of the detection frame, If the detection frame that has protruded from the set, the detection frame expanded in the protruding direction is set in the screen of the image data, and the method of recognizing the substrate mark using the expanded detection frame, The said subject is solved.

And in invention of Claim 2, in the board | substrate mark recognition method of the electronic component mounting machine of Claim 1, when the detection frame cannot be expanded in the screen of the said image data, the said board mark is from the said detection frame. The image pickup device is moved in a protruding direction, the substrate is picked up again by the image pickup device at the moved position, and the substrate mark is recognized using the image data picked up again. .

Furthermore, in the invention described in claim 3, the image data captured by the substrate mark recognition device of the electronic component mounting machine that images the substrate on which the electronic component is mounted by the imaging device and recognizes the positioning substrate mark on the substrate. An image data storage unit, a detection frame setting unit for setting a detection frame in the image data screen, an extraction data position designating unit for designating a position for extracting image data in the detection frame, An extraction data storage unit that extracts and stores image data from the position of the image data specified by the extraction data position specification unit, the calculation of the center of gravity position of the substrate mark from the storage data of the extraction data storage unit, and the substrate mark from the detection frame The above-mentioned problem is solved by comprising a substrate mark position calculation unit for calculating whether or not it is protruding.

According to a third aspect of the present invention, in the board mark recognition apparatus for an electronic component mounting machine according to the third aspect, when the detection frame cannot be enlarged in the screen of the image data, the board mark is removed from the detection frame. The imaging device is moved in the protruding direction, the substrate is again picked up by the imaging device at the moved position, and the substrate mark is recognized using the image data picked up again.

  According to the substrate mark recognition method and apparatus in the electronic component mounting machine of the present invention, image processing is performed on the image data in the detection frame in the captured image of the board mark, and the substrate mark protrudes from the detection frame. Recognize whether or not And if it is sticking out, the detection frame is enlarged to the sticking out side, and image processing is performed on the image data corresponding to the range of the enlarged detection frame, so that the recognition failure of the substrate mark is eliminated. At the same time, since the detection frame is expanded to the minimum necessary, the time required for image processing can be greatly reduced.

  Furthermore, if the substrate mark protrudes from the detection frame and the screen, the image processing is performed again by moving the imaging device to the protruding area, and image processing is performed again so that the substrate mark cannot be recognized. Can eliminate the problem.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an electronic component mounting apparatus in which a board mark recognition apparatus according to an embodiment of the present invention is incorporated. 2 is a block diagram showing a system configuration, FIG. 3 is an image diagram showing a detection frame, FIG. 4 is an image diagram when the detection frame cannot be enlarged, and FIG. 5 is a flowchart showing an operation of position recognition using image processing. .

  First, the overall structure of the substrate mark recognition apparatus 1 will be described with reference to FIG. In FIG. 1, reference numeral 15 denotes a substrate standard runway. A substrate 20 transported by the substrate running path 15 is held near the central portion of the substrate running path 15. A substrate mark 20 a is provided on the upper surface of the substrate 20. The mounting head unit 13 is supported by the XY transfer unit 14 and can move horizontally. The mounting head unit 13 is provided with a CCD camera 17 as an imaging device for imaging the substrate mark 20a. When the substrate mark 20 is imaged, the CCD camera 17 is moved so as to be positioned above the substrate mark 20a. Then, the substrate mark 20a is imaged, and the center of gravity position of the substrate mark 20a is obtained by image recognition, and the amount of deviation of the center of gravity position from the center position of the imaging screen (XY coordinate position deviation in the screen) is calculated. Since the relationship between the center position of the imaging screen of the CCD camera 17 and the XY coordinate position of the electronic component mounting machine 1 is known, the position of the substrate 20 relative to the XY coordinates of the electronic component mounting machine 1 is determined. Further, the mounting head portion 13 is provided with a nozzle 13a. The mounting head unit 13 vacuum-sucks the chip component supplied by the tape 11a wound on the reel 11 of the feeder 12 to the lower end of the nozzle 13a, corrects the position relative to the normal substrate position, and mounts it on the substrate 20.

Next, the configuration of the control system of the substrate mark recognition apparatus will be described with reference to FIG. In FIG. 2, the CCD camera 17 substrate mark 20 a is imaged, and the image data is sent to the image storage unit 23 via the A / D conversion unit 22. The image storage unit 23 stores the A / D converted image data. The detection frame setting unit 26 specifies the default detection frame size in the extracted data position specifying unit 27. The extracted data position specifying unit 27 calculates the address of the image data extracted from the image storage unit 23 according to the size of the extraction frame. The extracted data storage unit 24 extracts and stores image data from the image storage unit 23 according to the address indicated by the extracted data position specifying unit 27.

  The board mark position calculation unit 25 calculates the position of the center of gravity of the board mark 20a and checks whether the board mark 20a protrudes from the detection frame (whether the board mark 20a does not overlap the side of the detection frame) (see FIG. 3). ). If not protruding, the center of gravity position of the substrate mark 20a is transmitted to the main control unit 28, and if it is protruding, a detection frame enlargement command and an enlargement direction are sent to the detection frame setting unit 26. When the detection frame cannot be enlarged, a movement request command and movement direction of the CCD camera 17 are transmitted to the main control unit 28.

  The substrate mark 20a is generally attached to two or three of the four corners of the substrate. By imaging these board marks 20a and calculating the position of the center of gravity of the board marks 20a, the board position (XY coordinate position) in the electronic component mounting apparatus 1 is calculated. By recognizing the plurality of substrate marks 20a, the inclination of the substrate 20 with respect to the XY coordinates is also calculated. Based on this result, the mounting position (XY coordinate position) of the chip component is calculated, the mounting head 13 is moved by the XY transfer unit 14, and the nozzle 13a is rotated by θ to correct the tilt of the substrate, thereby correcting the chip component. Mounted on the substrate 20.

Here, the detection frame 31 will be described with reference to FIGS. 3 and 4. In FIG. 3, reference numeral 30 denotes a screen frame indicating the range of the screen imaged by the CCD camera 17, and the substrate mark 20a is imaged within this range. A range surrounded by a small solid line frame in the screen frame is the detection frame 31. The substrate mark 20a is imaged in a state of protruding from the detection frame 31 (a state in which the substrate mark 20a overlaps the right side of the detection frame 31). Reference numeral 32 denotes an enlargement position where the detection frame 31 is enlarged. The enlargement is performed by a distance slightly larger than the radius of the substrate mark 20a. In FIG. 3, the right side of the detection frame 31 is expanded rightward to a dotted line expansion position 32 to a distance slightly larger than the radius of the substrate mark 20a.

  The board mark position calculation unit 25 is a part that mainly recognizes the board mark 20a. The position of the substrate mark 20a is recognized by recognizing the substrate mark 20a and calculating the position of the center of gravity of the substrate mark 20a. For the gravity center position calculation by image recognition, a pattern matching method or a binarization method can be selected. When the board mark 20a can be clearly picked up, it is possible to select according to the state of the picked-up image because it takes less time to calculate the center of gravity of the board mark 20a from the image data by immediately binarizing the image data and calculating the center of gravity. It has become.

  Next, the distances from the center of gravity of the substrate mark 20a to the upper side, the lower side, the right side, and the left side of the detection frame 31 are calculated. If the distance is shorter than the radius of the substrate mark 20a, the substrate mark 20a bites away from the detection frame 31. It is determined that the image has been extracted, and the enlargement request for the detection frame 31 and the side to be enlarged are sent to the detection frame setting unit 26. Then, the image data extracted based on the enlargement request in the extraction data storage unit 24 is processed again, and if the substrate mark 20a does not protrude from the detection frame enlarged to the detection position 32, the center of gravity position of the substrate mark 20a is determined. Sent to the main control unit. Note that the calculation takes longer than before the enlargement.

In FIG. 4, 32 a indicates an enlargement position where the detection frame 31 is enlarged. The enlargement position 32a protrudes from the screen frame 30 to the outside of the screen frame 30, and the detection frame 31 cannot be enlarged. In this case, the CCD camera 17 is moved out and the substrate mark 20a is imaged again.

  When the detection frame setting unit 26 attempts to enlarge the detection frame 31 in response to an enlargement request from the board mark position calculation unit 25, but it is determined that the enlargement position 32a is outside the image frame 30 and cannot be enlarged, the detection frame enlargement setting is performed. The unit 24 sends to the substrate mark position calculation unit 25 the sides that cannot be enlarged (False) and cannot be enlarged. Then, the substrate mark position calculation unit 25 transmits a movement request command and a movement direction of the CCD camera 17 to the main control unit 28.

  Whether the board mark 20a protrudes from the detection frame 31 is determined by a threshold value in addition to the method of calculating and determining the distance from the center of gravity position to each side of the detection frame 31. There is. This is calculated by calculating whether there are more pixels than the threshold value specified by the pixel value in the image data (pixels) located on the upper side, the lower side, the right side, and the left side of the detection frame 31. If there are more, it is determined that the substrate mark 20a protrudes from the side. For example, if there are more pixels with a pixel value larger than the specified threshold value on the upper side, and there are more pixels with a pixel value larger than the specified threshold value on the right side than the specified number, the board It is determined that the mark 20a protrudes from the upper side and the right side of the detection frame 31.

  The configuration of the substrate mark recognition apparatus is as described above, and the operation thereof will be described below. First, the substrate 20 is transferred so as to be positioned at the center of the substrate transfer path 15. In FIG. 5, the mounting head unit 13 is horizontally moved by the XY transfer unit 14 so that the CCD camera 17 mounted on the mounting head unit 13 is positioned on the substrate mark 20a (ST1). Next, the substrate mark 20a is imaged by the CCD camera 17 (ST2). Image data (value of each pixel) corresponding to the detection frame is extracted from the image storage unit 23 and stored (ST3).

  Next, the position of the center of gravity of the substrate mark 20a is calculated, and a branch is made as to whether or not it is selected to check whether or not the protrusion is detected based on the distance from the position of the center of gravity to each side of the detection frame 31. Although not particularly described in the flowchart, the center of gravity calculation can be selected from a pattern matching method and a binarization method (ST4). If the distance from the center of gravity to the side is selected, the extracted image data is calculated to calculate the position of the center of gravity of the substrate mark 20a (ST5). Then, each distance from the barycentric position to each side (upper side, lower side, right side, left side) is calculated (ST6).

  If each distance is smaller than the radius of the substrate mark, it is judged that there is protrusion, and if all the distances are large, it is judged that there is no protrusion (ST7). If there is no protrusion, the position of the center of gravity of the substrate mark 20a is transmitted to the main controller 28 (ST13). If there is protrusion, the detection frame 31 is enlarged toward the protrusion. The amount to be enlarged is a value slightly larger than the radius of the substrate mark 20a or a value designated in advance (ST8).

  Next, it is determined whether the detection frame has been enlarged within the screen frame 30 or whether the detection frame has popped out of the screen frame 30 and cannot be enlarged (ST9). If it cannot be enlarged, a movement request command and a movement direction are transmitted to the main control unit 28 (ST14). After ST14, the position of the CCD camera 17 is changed by the XY transfer unit 14, and the substrate mark 20a is imaged again. When the detection frame 31 can be enlarged in the screen frame 30, the corresponding image data is extracted in the enlarged detection frame by returning to ST3.

  The case where the protrusion check is selected at the center of gravity position in ST4 will be described. In this case, the image data corresponding to each side of the detection frame 31, that is, the pixel value of the pixel at the position corresponding to each side is extracted (ST10). Next, it is determined whether or not there are more pixel values than the specified number for each side with respect to the extracted pixel values (ST11). If there are more sides than the specified number of pixel values greater than the threshold value, the substrate mark 20a protrudes from the sides, so that the process proceeds to ST8 and the detection frame 31 is enlarged. If there are no sides where there are more pixel values than the specified number, the image data extracted in ST3 is calculated to calculate the position of the center of gravity of the substrate mark 20a (ST12). Then, the substrate mark position is transmitted to the main control unit 28 (ST13).

  Although the substrate mark is described as a circle, it may be a symbol such as plus, triangle or square. The radius of the described substrate mark is the radius of the smallest circle that can enclose these symbols.

  As another application field, mark recognition for positioning the submount can be performed, and it can be used for a die bonder in which a laser diode chip is mounted on the submount.

It is a perspective view of the electronic component mounting apparatus with which the board | substrate mark recognition apparatus was integrated. It is a block diagram which shows a system configuration. It is an image figure which shows a detection frame. It is an image figure when a detection frame cannot be expanded. It is a flowchart which shows the operation | movement of position recognition using an image process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic component mounting machine 13 Mounting head part 13a Nozzle 14 XY transfer part 15 Substrate conveyance path 17 CCD camera (imaging device)
20 Substrate 20a Substrate mark 22 A / D conversion unit 23 Image storage unit 24 Extracted data storage unit 25 Substrate mark position calculation unit 26 Detection frame setting unit 27 Extracted data position designation unit 28 Main control unit 30 Screen frame 31 Detection frame 32 Enlarged position 32a Enlarged position

Claims (4)

  In the board mark recognition method for an electronic component mounter that recognizes a board mark for positioning on a board by imaging a board on which an electronic component is mounted with an imaging device, a detection frame is set in a screen of image data, and Recognize the substrate mark in the detection frame, recognize if the substrate mark protrudes from the detection frame for each side of the detection frame, and if the substrate mark protrudes from the detection frame A detection mark enlarged in a protruding direction is set in the screen of the image data, and the board mark is recognized using the enlarged detection frame. Method.   When the detection frame cannot be enlarged in the screen of the image data, the imaging device is moved in the direction in which the substrate mark protrudes from the detection frame, and the substrate is imaged again by the imaging device at the moved position. The board mark recognition method for an electronic component mounting machine according to claim 1, wherein the board mark is recognized using the image data picked up again.   In a board mark recognition device of an electronic component mounting machine that images a board on which an electronic component is mounted with an imaging device and recognizes a positioning board mark on the board, an image data storage unit that stores captured image data; A detection frame setting unit for setting a detection frame in a screen of image data, an extraction data position designating unit for designating a position for extracting image data within the detection frame, and image data designated by the extraction data position designating unit An extraction data storage unit that extracts and stores image data from the position of the substrate, and calculates the center of gravity position of the substrate mark from the storage data of the extraction data storage unit and calculates whether the substrate mark protrudes from the detection frame An apparatus for recognizing a board mark of an electronic component mounting machine, comprising: a board mark position calculation unit for commanding an enlargement of the detection frame if protruding. If the detection frame cannot be enlarged in the screen of the image data, the imaging device is moved in a direction in which the substrate mark protrudes from the detection frame, and the substrate is again moved by the imaging device at the moved position. 4. The board mark recognition apparatus for an electronic component mounting machine according to claim 3, wherein the board mark is recognized using the image data picked up again.

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