JP2008298462A - Apparatus and method for inspecting printed mask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed mask inspection apparatus and a printed mask inspection method capable of easily inspecting a printed mask with high accuracy. <P>SOLUTION: The printed mask inspection apparatus inspects the printed mask to be used when electronic components are mounted on a board. An image acquisition means acquires an image of a plurality of through holes formed in the printed mask by a scanner. A measurement means measures the plurality of through holes based on the image, and a display control means displays the measurement results. By the printed mask inspection apparatus, the plurality of through holes formed in the printed mask can be measured easily by using a relatively inexpensive scanner being currently on the market or the like. Concretely, through holes of minute size can be measured with high accuracy, and moreover multiple through holes can be measured in a short time. Accordingly, it is made possible to inspect a printed mask with high accuracy. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a printing mask inspection apparatus and a printing mask inspection method for inspecting a printing mask used when an electronic component is mounted on a substrate.

  Conventionally, a printing mask is used when an electronic component is mounted on a substrate. Specifically, solder is supplied onto a printed circuit board from a through hole formed in a printing mask, and an electronic component is placed on the printed circuit board in a state where an electrode is in contact with the solder. For example, Patent Document 1 describes a mask device capable of accurately performing solder printing. Patent Document 2 describes an apparatus for inspecting a design shape of a through hole (hole) formed in a printing mask in advance.

JP 2001-199038 A JP-A-9-61130

  However, with the techniques described in Patent Documents 1 and 2 described above, it has been difficult to accurately inspect the print mask without requiring labor.

  Examples of the problem to be solved by the present invention are as described above. It is an object of the present invention to provide a printing mask inspection apparatus and a printing mask inspection method that can easily perform high-precision inspection of a printing mask.

  According to the first aspect of the present invention, the printing mask inspection apparatus for inspecting the printing mask used when mounting the electronic component on the substrate acquires images of the plurality of through holes formed in the printing mask by the scanner. An image acquisition unit that performs measurement on a plurality of through holes formed in the print mask based on the image acquired by the image acquisition unit, and display control that displays a measurement result by the measurement unit And means.

  In the invention described in claim 11, a printing mask inspection method for inspecting a printing mask used when mounting an electronic component on a substrate acquires images of a plurality of through holes formed in the printing mask by a scanner. An image acquisition step, a measurement step for measuring a plurality of through holes formed in the print mask based on the image acquired by the image acquisition step, and a display control for displaying a measurement result by the measurement step And a process.

  In one embodiment of the present invention, a printing mask inspection apparatus that inspects a printing mask used for mounting electronic components on a substrate acquires images of a plurality of through holes formed in the printing mask using a scanner. An image acquisition unit that performs measurement on a plurality of through holes formed in the print mask based on the image acquired by the image acquisition unit, and display control that displays a measurement result by the measurement unit Means.

  The above-described printing mask inspection apparatus is preferably used to inspect a printing mask used when an electronic component is mounted on a printed circuit board or the like. Specifically, the image acquisition unit acquires images of a plurality of through holes formed on the print mask by the scanner. And a measurement means measures with respect to the several through-hole formed in the printing mask based on the acquired image, and a display control means displays a measurement result. According to the above-described printing mask inspection apparatus, it is possible to perform high-precision measurement without using a microscope or the like for a through hole having a small size for soldering a minute electronic component. Further, since a scanner is used, it is possible to appropriately measure even a print mask that is difficult to measure with a microscope due to size reasons. Furthermore, according to the above-described printing mask inspection apparatus, it is possible to measure a large number of through holes at once, in other words, it is possible to measure a large number of through holes in a short time. As described above, according to the above-described printing mask inspection apparatus, it is possible to easily perform high-precision measurement for a plurality of through holes formed in the printing mask, and to accurately inspect the printing mask. It becomes.

  In one aspect of the above-described printing mask inspection apparatus, the image processing apparatus further includes a scale image acquisition unit that acquires a scale image in which a scale on which a plurality of line segments or a plurality of marks are regularly arranged is drawn is captured by the scanner. The measurement unit performs a process of restoring the image acquired by the image acquisition unit based on the plurality of line segments or the plurality of marks in the scale image acquired by the scale image acquisition unit, The measurement is performed based on the restored image.

  In this aspect, the printing mask inspection apparatus performs a process of restoring the printing mask image by correcting distortion, shift, and the like occurring in the printing mask image obtained by photographing based on the scale image. . By performing measurement based on the image restored in this manner, it is possible to perform highly accurate measurement on the through-hole formed in the print mask.

  In another aspect of the above-described printing mask inspection apparatus, the image acquisition unit is in a state in which black paper is covered on a region where the through hole of the printing mask that is opposite to the reading surface of the scanner is formed. Then, the image is acquired. As a result, when an image expressed in black and white is acquired, it is possible to acquire an image of a print mask in which the through hole portion is clearly visible.

  Preferably, in the above-described printing mask inspection apparatus, the measuring unit can measure at least one of coordinates, shapes, sizes, directions, and areas in the plurality of through holes.

  Preferably, the display control means can display at least an image corresponding to the print mask and an image corresponding to the measurement data of the through hole measured by the measurement means. Further, the display control means searches for the through-holes existing in the selected region in the image corresponding to the printing mask, and classifies the measured data in the searched through-holes according to the type of data as a table. While displaying, the said through-hole which exists in the selected area | region can be made into a drawing, and can be displayed as a map. Based on the image displayed in this way, it is possible to appropriately inspect the print mask.

  More preferably, the display control means, when any of a through hole in the image corresponding to the print mask, a row in the table indicating the measurement data, and a through hole in the map is selected, In each of the image corresponding to the mask, the table indicating the measurement data, and the map, the image corresponding to the selected content can be displayed in conjunction with each other. Thereby, it is possible to promptly display an enlarged image in the defective portion.

  Preferably, the display control means displays data sorted by a combination of at least one of coordinates, shape, size, direction, and area in the through hole measured by the measurement means. it can.

  Preferably, statistical processing means is further provided for performing statistical processing on an error between the through hole data measured by the measuring means and the through hole data in the gerber data of the printing mask. By using the result of such statistical processing, it is possible to appropriately inspect the print mask.

  More preferably, the printing mask inspection apparatus can take an image with the scanner while the scanner is placed on a base plate. Thereby, it is possible to improve the repeatability of shooting, and it is possible to increase the accuracy of restoration correction of a shot image.

  In another aspect of the present invention, a printing mask inspection method for inspecting a printing mask used when an electronic component is mounted on a substrate acquires images of a plurality of through holes formed in the printing mask using a scanner. An image acquisition step, a measurement step for measuring a plurality of through holes formed in the print mask based on the image acquired by the image acquisition step, and a display control step for displaying a measurement result by the measurement step And comprising. Even with the above-described printing mask inspection method, it is possible to easily perform high-precision measurement for a plurality of through holes formed in the printing mask using a relatively inexpensive scanner or the like. It becomes possible to carry out with high accuracy.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[System configuration]
First, the configuration of a system to which a printing mask inspection apparatus according to an embodiment of the present invention is applied will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of a printing mask inspection system 100.

  The printing mask inspection system 100 includes a personal computer (PC) 1 and a scanner 2. The print mask inspection system 100 mainly inspects a print mask (not shown). The scanner 2 captures an image of an object placed on the reading surface 2x, and supplies image data S2 obtained by the capture to the PC 1. For example, as the scanner 2, a known flatbed scanner, a sheet feed scanner, a film scanner, or the like can be used. Further, the scanner 2 having a resolution of about 7200 DPI (3.5 μm / pix) can be used. In this embodiment, the scanner 2 mainly performs photographing on a print mask.

  The PC 1 includes an arithmetic processing unit 1a and an image display unit 1b. The arithmetic processing unit 1a includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and performs image processing on the image data S2 supplied from the scanner 2. Specifically, the arithmetic processing unit 1a performs image processing for correcting distortion, deviation, and the like that occur in the image of the print mask obtained by photographing. In other words, the arithmetic processing unit 1a performs image processing for generating an image obtained by restoring an image (hereinafter referred to as “restored image”). Then, the arithmetic processing unit 1a performs measurement on the print mask based on the restored image obtained by the image processing. Further, the arithmetic processing unit 1a performs processing for displaying the measurement result and the like on the image display unit 1b.

  In this way, the arithmetic processing unit 1a functions as a printing mask inspection apparatus according to the present invention. Specifically, the arithmetic processing unit 1a operates as an image acquisition unit, a measurement unit, a display control unit, a scale image acquisition unit, and a statistical processing unit. On the other hand, the image display unit 1b displays an image photographed by the scanner 2, a restored image image-processed by the arithmetic processing unit 1a, a measurement result of a print mask, and the like.

[Print mask inspection method]
Below, the inspection method of the printing mask which the arithmetic processing part 1a performs is demonstrated concretely.

  In this embodiment, the arithmetic processing unit 1 a acquires a print mask image (hereinafter also referred to as “print mask image”) by the scanner 2. Specifically, images of a plurality of through holes formed on the printing mask are acquired as printing mask images. And the arithmetic processing part 1a performs the measurement with respect to the several through-hole formed in the printing mask based on the acquired printing mask image. For example, the arithmetic processing unit 1a measures the coordinates, shape, size, direction, area, and the like in the through hole.

  More specifically, the arithmetic processing unit 1a acquires an image (hereinafter referred to as “scale image”) in which a scale on which a pattern in which a plurality of line segments or a plurality of marks are regularly arranged is drawn is captured by the scanner 2. Then, based on the acquired scale image, the above-described print mask image is restored. And the arithmetic processing part 1a performs the measurement with respect to the several through-hole formed in the printing mask based on the acquired restored image. As described above, it is possible to easily inspect the printing mask with high accuracy.

  Next, a printing mask inspection method according to the present embodiment will be described in detail with reference to FIGS.

  FIG. 2 is a diagram for explaining a method of capturing a scale image used for restoring a print mask image. Note that the scale image is used to correct distortions and shifts generated in the print mask image due to the characteristics of the scanner 2 and the like. In addition, the acquisition of the scale image is basically executed before photographing the print mask or inspecting the print mask.

  FIG. 2A shows the scale 3 used in this embodiment. The scale 3 is composed of a glass plate or the like, and has a lattice 3a. Specifically, the scale 3 has a pattern in which a plurality of vertical line segments and horizontal line segments are arranged at equal intervals so as to be orthogonal to each other. In this case, for example, the interval of the grating 3a is set to about 7 (mm), and the allowable error is set to “± 4 (μm)” or “± 8 (μm)”. The scale 3 functions as a glass gauge.

  FIG. 2B is a diagram showing how the scale 3 is set in the scanner 2. In this case, the scale 3 is placed on the reading surface 2x of the scanner 2. FIG. 2C is a diagram illustrating an example of the scale image 13 acquired by the scanner 2. From this, it can be seen that the lattice image 13a in the scale image 13 is distorted. This is due to the characteristics of the scanner 2 and the like. In the present embodiment, the arithmetic processing unit 1a quantifies the accuracy distribution of the scanner 2 from such distortion and deviation generated in the scale image 13, and stores the quantified accuracy distribution. Then, the arithmetic processing unit 1a restores the print mask image based on the digitized accuracy distribution of the scanner 2.

  In addition, although the example using the scale 3 on which the lattice 3a is drawn has been described above, the present invention is not limited to this. In another example, instead of using such a scale 3, a scale on which a pattern in which a plurality of marks (dots) are regularly arranged can be used.

  FIG. 3 is a diagram illustrating an example of a print mask. FIG. 3A is a diagram showing a schematic configuration of the mask device 6 having the printing mask 7. The mask device 6 has a size of about 600 × 550 to 1100 × 800 (mm), and mainly includes a printing mask 7 and a frame portion 9 that supports and fixes the printing mask 7. The mask device 6 is basically used for supplying solder to the printed circuit board according to a predetermined pattern required for driving an electronic component (not shown) mounted on the printed circuit board (not shown).

  FIG. 3B is a view of the printing mask 7 observed from above. The printing mask 7 is formed on a flat plate made of a metal such as hard nickel. Further, the printing mask 7 has a plurality of through holes 8a (see FIG. 3B). The through-hole 8a is formed in the printing mask 7 according to the location where the solder on the printed circuit board is to be supplied using the printing mask 7. In the following, the region in the printing mask 7 in which the through-hole 8a is formed (corresponding to a colored portion in FIG. 3A, which is a subject to be photographed by the scanner 2 in this embodiment, FIG. , Which corresponds to the portion indicated by a broken line) is referred to as a through-hole portion 8.

  Here, a procedure for mounting an electronic component on a printed board using the mask device 6 will be briefly described. First, the mask device 6 is positioned with the print mask 7 facing the printed circuit board. Thereafter, the squeegee (not shown) presses the print mask 7 in a direction approaching the printed circuit board, and the squeegee is moved on the print mask 7 along the print mask 7. Thereby, solder (so-called cream solder) is pushed out from the through-holes 8a formed in the printing mask 7, whereby the solder is supplied to predetermined positions on the surface of the printed circuit board. Thereafter, the printed circuit board on which the electronic components are placed is placed in a reflow furnace, and the solder is remelted, whereby the electronic components are collectively mounted on the printed circuit board.

  FIG. 4 is a diagram for specifically explaining a method of setting the mask device 6 on the scanner 2.

  FIG. 4A is a diagram illustrating a state where the rear cover 2y of the scanner 2 is removed. In this embodiment, a print mask image is acquired with the back cover 2y removed. This is because the mask device 6 tends to have a larger size than the scanner 2. FIG. 4B is a diagram showing how the mask device 6 is set in the scanner 2. Specifically, the mask device 6 is set in the scanner 2 so that the through hole portion 8 in which the through hole 8a is formed is placed on the reading surface 2x of the scanner 2 from which the back cover 2y is removed. Next, FIG. 4C is a diagram showing a state in which the black paper 10 is put on the through hole portion 8 on the opposite side of the reading surface 2x of the scanner 2. In the present embodiment, photographing with respect to the printing mask 7 is performed in such a state that the black paper 10 is covered on the through-hole portion 8 as described above. This is because when a black and white image is acquired as a print mask image, a print mask image in which the portion of the through hole 8a is clearly visible is acquired. Note that it is not necessary to use such black paper 10 when the print mask image is acquired as a color image.

  FIG. 5 is a diagram for explaining a method for capturing a print mask image and a restoration method for the print mask image.

  FIG. 5A shows an image 20 before the print mask 7 is captured as a print mask image. In other words, the image 20 corresponds to a preview image used for capturing a print mask image. A person who performs measurement (hereinafter also simply referred to as “measurer”) refers to the image 20 and designates the imaging range of the scanner 2. For example, the measurer designates the imaging range so that all the images 21 corresponding to the through-hole portion 8 are included. In this case, the measurer can specify the shooting range by operating the mouse (not shown) of the PC 1 based on the image displayed on the image display unit 1b. Thus, after the designation of the photographing range is finished, photographing is performed by the scanner 2. In the above description, an example in which the measurer manually designates the photographing range has been described. However, instead of this, the arithmetic processing unit 1a can automatically set the photographing range by recognizing the print mask 7 as an image. is there.

  FIG. 5B shows a print mask image 30 photographed by the scanner 2. This print mask image 30 corresponds to an image photographed based on the photographing range designated by the measurer. The printing mask image 30 obtained by photographing is stored in the arithmetic processing unit 1a as bitmap data or the like. Looking at the print mask image 30, it can be seen that distortion has occurred. Specifically, it can be seen that the image 18a corresponding to the through-hole 8a is largely deviated from the assumed position. This is due to the characteristics of the scanner 2 and the like.

  FIG. 5C shows a restored image 40 obtained by restoring the print mask image 30. The arithmetic processing unit 1a performs image processing for restoring the print mask image 30 based on the accuracy distribution of the scanner 2 digitized when the scale image is acquired (see FIG. 2). Specifically, the arithmetic processing unit 1a performs processing for restoring the print mask image 30 based on the position of the grid in the scale image. For example, the arithmetic processing unit 1a performs restoration by the following procedure. First, the arithmetic processing unit 1a calculates the position on the print mask image 30 corresponding to the pixel position of the restored image 40 to be obtained by restoration based on the position of the grid in the scale image. Next, the arithmetic processing unit 1a obtains data to be assigned to the position on the obtained print mask image 30 by interpolating using data around the position. By performing the above processing on all the pixels constituting the restored image 40, the restored image 40 corresponding to the print mask image 30 is obtained. As a result, a restored image 40 can be obtained in which the influence of distortion and displacement due to the characteristics of the scanner 2 is eliminated. In the present embodiment, the arithmetic processing unit 1a performs measurement on the through hole 8a formed in the print mask 7 based on the restored image 40 thus obtained.

  By measuring the through hole 8a as described above, it is possible to perform high-precision measurement without using a microscope or the like for the through hole 8a having a small size for soldering a minute electronic component. it can. In the present embodiment, since the measurement is performed using the scanner 2, it is possible to appropriately perform measurement even for a printing mask that is difficult to measure with a microscope for reasons of size. Furthermore, according to the present embodiment, measurement can be performed at once for a large number (for example, several thousand) of through holes 8a, in other words, measurement can be performed for a large number of through holes 8a in a short time. it can. As described above, according to the printing mask inspection system 100 according to the present embodiment, high-precision measurement can be easily performed on the plurality of through-holes 8a formed in the printing mask 7, and the printing mask 7 can be inspected. Can be performed with high accuracy.

  FIG. 6 is a diagram illustrating an example of a display image showing the measurement result of the print mask 7. In FIG. 6A, an image indicated by reference sign A2 indicates an image indicating the through-hole portion 8 (assuming a restored image). The image indicated by reference sign A1 shows a map of the measured through-hole 8a. Specifically, this map is a drawing of the through-holes 8a existing in the region selected by the measurer in the print mask image. Further, the image indicated by reference numeral A3 corresponds to the image shown in the table with the measurement data in each of the plurality of through holes 8a. Specifically, this table displays the measurement data of the through holes 8a existing in the region selected by the measurer in the print mask image, classified according to the type of data. For example, measurement data such as coordinates, shapes, sizes, directions, and areas in the plurality of through holes 8a are displayed in this table. In this way, by selecting a region to be measured in the print mask image by dragging the mouse with a mouse or the like, the through hole existing in the region can be obtained without giving information on the measurement data of the through hole 8a in advance. The above-described table and map can be displayed by automatically searching 8a and measuring the searched through-hole 8a.

  Further, FIG. 6B is a diagram showing the measurement result of the through-hole 8a existing in the selected region on the print mask image (assuming the restored image). In this case, the measurer selects the through-hole 8a to be measured on the print mask image with a mouse or the like (specifically, by dragging with the mouse, a rectangular range as indicated by reference numeral A5 is designated) By pressing the measurement button, the measurement data of the selected through hole 8a is displayed. In this example, the number, coordinates (X coordinate, Y coordinate), shape, and size (long side, short side, height) in the selected through hole 8a are displayed.

  The arithmetic processing unit 1a moves the cursor to the corresponding row in the table showing the measurement data when the measurer clicks the image showing the through hole 8a on the image as shown in FIG. Can be made. Further, when the measurer clicks on a line of measurement data, the arithmetic processing unit 1a can move the cross cursor to an image showing the corresponding through hole 8a in the print mask image.

  Further, in the image as shown in FIG. 6A, the arithmetic processing unit 1a has a through hole 8a in the print mask image indicated by reference numeral A2, a row in a table indicating measurement data indicated by reference numeral A3, and indicated by reference numeral A1. When the measurer selects any of the through-holes 8a in the map, an image corresponding to the selected content can be displayed in conjunction with each of these print mask images, tables, and maps. In other words, when the through-hole 8a in the print mask image, the row in the table, and the through-hole 8a in the map are clicked, the arithmetic processing unit 1a links these three images to obtain the same through-hole 8a (measurement). (Including data) can be displayed.

  For example, when an arbitrary row in the table is clicked, the row becomes blue or the like, the enlarged image in the through hole 8a of the print mask image indicated by the information moves to the center of the screen, and the cross cursor is centered on the through hole 8a. Display. At the same time, the map displays the entire area of the through-hole 8a. At the same time, the cross-cursor indicates where the through-hole 8a corresponding to the clicked measurement data exists, and the image is displayed. The range that is magnified is displayed as a rectangle. On the other hand, when the map is clicked or when the print mask image is clicked, the through hole 8a closest to the clicked coordinate is retrieved, and the through hole 8a in the print mask image, the row in the table, and the map The images indicating the respective through-holes 8a are linked to display the same through-hole 8a (including measurement data). By performing such display, it is possible to promptly display an enlarged image in the defective portion.

  Moreover, the arithmetic processing part 1a can display the data sorted by the combination by the coordinate in the some through-hole 8a, shape, size, direction, area, etc. as a table | surface which shows the measurement result of the through-hole 8a. In addition, the arithmetic processing unit 1a can make the measured through-holes 8a non-standard items stand out on the image and display them. For example, when the measured data such as coordinates, shape, and size of the through hole 8a is more than a predetermined distance from the data of the through hole 8a in the Gerber data of the printing mask 7, an image showing the through hole 8a is displayed in red. Can be made.

  FIG. 7 is a diagram for explaining a method of measuring a plurality of through holes 8a at once by labeling an image. In this case, the measurer selects a plurality of through holes 8a to be measured on the print mask image (representing the restored image) with a mouse or the like (specifically, by dragging with the mouse, (Specify a rectangular range as indicated by reference numeral B1) and press the measurement button. Thereafter, the arithmetic processing unit 1a performs a labeling process on the selected image, and measures a plurality of through holes 8a existing in the selected image at a stretch.

  FIG. 8 is a diagram for explaining a statistical process performed on an error between the print mask image and the Gerber data used when the print mask 7 is created. In FIG. 8, an image indicated by reference numeral C1 indicates a print mask image obtained by photographing (assuming a restored image), and an image indicated by reference numeral C2 indicates a print mask image created with Gerber data. In this case, the arithmetic processing unit 1a compares (collates) the data of the through-hole 8a in the print mask image C1 obtained by photographing with the data of the through-hole 8a in the print mask image C2 created by the Gerber data, Statistical processing is performed on these errors. And the arithmetic processing part 1a displays the result of a statistical process on the image display part 1b. Note that, as described above, instead of performing statistical processing using a print mask image created with Gerber data, statistical processing may be performed using the value of Gerber data itself.

  In addition to the statistical processing as described above, the arithmetic processing unit 1a can perform statistical processing on the sorted data of the through holes 8a having substantially the same size. Specifically, the arithmetic processing unit 1a performs statistical processing on data (for example, data selected in units of a plurality of rows) selected by a measurer in data having substantially the same value.

[Print mask image acquisition processing]
Next, with reference to FIG. 9, a print mask image acquisition process in this embodiment will be described. FIG. 9 is a flowchart showing print mask image acquisition processing. This processing is mainly executed by the arithmetic processing unit 1a of the PC1. In the flowchart of FIG. 9, the process indicated in parentheses indicates the process performed by the measurer.

  First, in step S <b> 101, the measurer sets the scale 3 on the scanner 2. In this case, the measurer sets the scale 3 at a predetermined position on the reading surface 2x of the scanner 2. Then, the process proceeds to step S102.

  In step S102, the scanner 2 executes scale 3 imaging. The scanner 2 supplies the scale image obtained by photographing to the arithmetic processing unit 1a as a signal S2. In this case, the arithmetic processing unit 1a quantifies the accuracy distribution of the scanner 2 from the distortion generated in the acquired scale image and stores the quantified accuracy distribution. Then, the process proceeds to step S103.

  In step S103, the measurer removes the scale 3 from the scanner 2, and then removes the back cover 2y of the scanner 2. Then, the process proceeds to step S104. If the print mask 7 can be appropriately placed on the reading surface 2x of the scanner 2 without removing the back cover 2y, the back cover 2y may not be removed.

  In step S <b> 104, the measurer sets the mask device 6 on the scanner 2. Specifically, the mask device 6 is set in the scanner 2 so that the through hole portion 8 in which the through hole 8a is formed is placed on the reading surface 2x of the scanner 2 from which the back cover 2y is removed. Then, the process proceeds to step S105.

  In step S <b> 105, the measurer puts the black paper 10 on the through hole portion 8 on the opposite side of the reading surface 2 x of the scanner 2. This is because when a black and white image is acquired, a print mask image in which the through hole 8a is clearly shown is acquired. In addition, when acquiring a color image, it is not necessary to cover such a black paper 10 on the through-hole part 8. FIG. When the above process ends, the process proceeds to step S106.

  In step S <b> 106, the measurer refers to the image (preview image) displayed on the image display unit 1 b and designates the shooting range by the scanner 2. Specifically, the measurer designates the photographing range so that the through-hole portion 8 to be photographed is captured by the scanner 2. Then, the process proceeds to step S107.

  In step S107, the printing mask 7 is photographed based on the photographing range designated by the measurer in step S106. In this case, the arithmetic processing unit 1a stores an image (print mask image) obtained by photographing as bitmap data. Then, the process proceeds to step S108.

  In step S108, the arithmetic processing unit 1a executes image processing for restoring the print mask image acquired in step S107 based on the scale image acquired in step S102. In this case, the arithmetic processing unit 1a performs image processing for restoring the print mask image based on the digitized accuracy distribution of the scanner 2. Specifically, the arithmetic processing unit 1a performs processing for restoring the print mask image based on the position of the lattice in the scale image. When the above process ends, the process exits the flow.

  As described above, according to the print mask image acquisition processing according to the present embodiment, it is possible to easily increase the height of the plurality of through-holes 8a formed in the print mask 7 using a relatively inexpensive commercially available scanner. It becomes possible to measure the accuracy. Specifically, highly accurate measurement can be performed on through holes 8a having a small size for soldering minute electronic components, and a large number (for example, thousands) of through holes 8a can be measured. Measurement can be performed at once in a short time. Therefore, it is possible to accurately inspect the print mask 7.

  As described above, in the present embodiment, the arithmetic processing unit in the PC that inspects the print mask used when mounting the electronic component on the substrate has a plurality of through holes formed in the print mask by the scanner. The image is acquired, and a plurality of through holes formed in the printing mask are measured based on the acquired image, and the measurement result is displayed. Thereby, it is possible to easily perform high-precision measurement for a plurality of through holes formed in the print mask using a relatively inexpensive commercially available scanner, and to accurately inspect the print mask. It becomes possible.

[Modification]
Imaging by the scanner 2 is preferably performed with the scanner 2 placed on a base plate. Specifically, it is preferable to perform imaging with respect to the scale 3 and imaging with respect to the printing mask 7 with the scanner 2 placed on the base plate. As a result, it is possible to improve the repeatability of photographing by the scanner 2 and to improve the restoration correction accuracy for the photographed image.

  FIG. 10 is a diagram illustrating an example of the base plate 80. FIG. 10A is a diagram showing how the scanner 2 is placed on the base plate 80. The base plate 80 has a slightly larger size than the scanner 2. Specifically, the upper surface of the base plate 80 has such a size that the bottom surface of the scanner 2 does not protrude from the base plate 80 when the scanner 2 is placed on the base plate 80. FIG. 10B is a diagram showing the configuration of the base plate 80. Specifically, a top view of the base plate 80 is shown on the upper side of FIG. 10B, and a side view of the base plate 80 is shown on the lower side of FIG. 10B. The base plate 80 is made of a material and a thickness that does not deform even when the scanner 2 is placed. For example, the base plate 80 is made of an aluminum plate having a thickness of about 20 (mm). Furthermore, three non-reaction rubber feet 80 a are provided at the lower part of the base plate 80. Therefore, when the base plate 80 is placed on a desk or the like, three points are supported by the non-reaction rubber feet 80a. Thereby, backlash can be suppressed effectively. Therefore, by performing imaging while the scanner 2 is placed on such a base plate 80, it is possible to improve the repetition accuracy of imaging, and it is possible to improve the restoration correction accuracy for the captured image.

It is a figure which shows schematic structure of the inspection system of the printing mask which concerns on a present Example. It is a figure for demonstrating the method to capture a scale image. It is a figure which shows an example of a printing mask. It is a figure for demonstrating the method to set a mask apparatus with respect to a scanner. It is a figure for demonstrating the method etc. which capture a printing mask image. It is a figure showing an example of the display image which shows the measurement result of a printing mask. It is a figure for demonstrating the method of measuring a several through-hole at a stretch. It is a figure for demonstrating the statistical process performed with respect to an error with a Gerber data. It is a flowchart which shows the acquisition process of the printing mask image which concerns on a present Example. It is a figure which shows an example of a baseplate.

Explanation of symbols

1 Personal computer (PC)
DESCRIPTION OF SYMBOLS 1a Arithmetic processing part 1b Image display part 2 Scanner 2x Reading surface 2y Back cover 3 Scale 6 Mask apparatus 7 Print mask 8 Through-hole part 8a Through-hole 100 Print mask inspection system

Claims (11)

A printing mask inspection apparatus for inspecting a printing mask used when mounting an electronic component on a substrate,
Image acquisition means for acquiring images of a plurality of through holes formed in the printing mask by a scanner;
Measuring means for measuring a plurality of through holes formed in the printing mask based on the image acquired by the image acquisition means;
And a display control means for displaying a measurement result obtained by the measurement means. A scale image acquiring means for acquiring a scale image captured by the scanner with a scale on which a pattern in which a plurality of line segments or a plurality of marks are regularly arranged is drawn;
The measurement unit performs a process of restoring the image acquired by the image acquisition unit based on the plurality of line segments or the plurality of marks in the scale image acquired by the scale image acquisition unit, The printing mask inspection apparatus according to claim 1, wherein the measurement is performed based on the restored image.   The image acquisition means acquires the image in a state where black paper is covered on a region where a through hole of the printing mask that is opposite to a reading surface of the scanner is formed. The printing mask inspection apparatus according to 1 or 2.   The printing mask according to claim 1, wherein the measuring unit measures at least one of coordinates, shapes, sizes, directions, and areas in the plurality of through holes. Inspection equipment.   The display control means displays at least an image corresponding to the printing mask and an image corresponding to the measurement data of the through hole measured by the measurement means. The printing mask inspection apparatus according to one item.   The display control means searches for the through-holes existing in a selected region in an image corresponding to the print mask, and displays the measurement data in the searched through-holes as a table classified by data type. The printing mask inspection apparatus according to claim 5, wherein the through-holes existing in the selected region are displayed as a map in a drawing.   The display control means, when any one of the through hole in the image corresponding to the print mask, the row in the table indicating the measurement data, and the through hole in the map is selected, the image corresponding to the print mask. The printing mask inspection apparatus according to claim 6, wherein an image corresponding to the selected content is displayed in conjunction with each other in each of the table indicating the measurement data and the map.   The display control means displays data sorted by a combination of at least one of coordinates, shape, size, direction, and area in the through hole measured by the measuring means. The printing mask inspection apparatus according to any one of 1 to 7.   The statistical processing means which performs a statistical process with respect to the difference | error of the data of the said through-hole measured by the said measurement means and the data of the through-hole in the Gerber data of the said printing mask is further provided. The printing mask inspection apparatus according to any one of claims 1 to 8.   The printing mask inspection apparatus according to claim 1, wherein photographing is performed by the scanner while the scanner is placed on a base plate. A printing mask inspection method for inspecting a printing mask used when mounting an electronic component on a substrate,
An image acquisition step of acquiring images of a plurality of through holes formed in the printing mask by a scanner;
Based on the image acquired by the image acquisition step, a measurement step for measuring a plurality of through holes formed in the printing mask,
And a display control step for displaying a measurement result obtained by the measurement step.

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