JP2003149161A - Method and apparatus for examining shadow mask, and program therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of automatically detecting defective portions to remove chip defects in place of an examining method based on human sensuality in defective examination of shadow masks. SOLUTION: The shadow mask examining method comprises steps of: indicating a stage stop position and a next movement destination position; registering in advance the position coordinate, an image pickup area, an image pickup magnification, reflection, transmission of illumination, a unit of data address, a segment address unit and a threshold value based on examination standard; repeating mounting on a stage, movement and stop of the stage and camera image pickup; recording of coordinate values of large and small holes on the basis of contrast ratio of a through hole and a dimension measurement; binary processing of image of the through hole extracted on the basis of the basis of the data address unit and the segment address unit; parallel processing using algorithms of two or more; judgment of the processing result; and identification of an examination-failed examination target as a chip defect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shadow mask inspection method for detecting a defective portion of a shadow mask, an apparatus therefor, and a program therefor.

[0002]

2. Description of the Related Art FIG. 6 is a drawing for explaining a shadow mask, (a) is a plan view of the shadow mask, (b) is a perspective side view of a through hole in which a part of a through hole arrangement area 10 is enlarged, c) is a side sectional view of the through hole. The standards for the cross-sectional shape of the through hole are strict, and the occurrence of defects is greatly affected by the defective shape in the vicinity of the through hole. Further, in the current shadow mask, the defective mixture ratio allowed at the time of shipment has become extremely severe, and the most severe allowable ratio is required to be 500 ppm or less.

There is a problem that a sensory test by a person cannot cope with the maintenance and management of the above defective mixture rate.

Therefore, a method of observing the defect inspection of the shadow mask with an electronic device such as a CCD camera and automatically judging whether the result is acceptable or not by using a computer has become mainstream.

For example, the defect inspection by an automatic inspection machine is incorporated and fixed in the inspection process.

In the above-mentioned automatic inspection machine of the prior art, the mode classification of the defective portion is as follows. (A) If the hole diameter of the through hole is larger than the standard value, it is a large hole defect, and (b) the hole diameter is If it is smaller than the standard value, it means that the hole is small, and (c) or the vicinity of the through-hole, for example, the portion excessively etched locally to the material region on the boundary line between the through-hole and the metal material surface in the cross section, or (1) defective parts that are locally under-etched in the through-hole region are defective, and (d) defective parts where residues such as foreign substances are attached to the surface of the metal material are defective. The defect is detected by classifying it into a defect of unevenness caused by the variation of (4) and another defect of (f).

As shown in FIG. 7, (a) shows a side cross-sectional view of a through hole which has passed the standard value, and (b) shows that the through hole has a larger diameter diameter than the standard value and is observed by, for example, transmitted light. In the case, of course, the light energy transmitted through the through hole increases and C
The density of the image captured by the CD camera also increases. Since the etching amount is too large, it is called a large hole defect. In (c), the through hole has a hole diameter smaller than the standard value. For example, when observed with transmitted light, the light energy transmitted through the through hole is naturally decreased, and the density of the image captured by the CCD camera is also decreased. Since the etching amount is too small, it is called a small hole defect.

Among the above-mentioned defect items, defects with large holes and defects with small holes are surely detected as defects by the inspection of the automatic inspection machine, and the shadow mask having such defects can be automatically selected and removed.

Other items such as defective chipping, defective spots, and unevenness are detected as defective by visual judgment by a sensory test by humans and manually removed.

FIG. 9 is a view for explaining the chip defect,
(A) And (b) is a top view which shows a defective chip | tip typically. (A) shows chipping defects that easily occur when the etching amount is large, and (b) shows chipping defects that easily occur when the etching amount is small. Further, (c) and (d) are side cross-sectional views, (c) shows chipping defects that easily occur when the etching amount is large, and (d) shows chipping defects that easily occur when the etching amount is small.

The chip defect shown in FIG. 9 has a variety of shapes of the defective portion, and the dimensions of the defective portion are complicatedly entangled with each other. Therefore, it tends to be difficult to extract the defective portion by simple division. Is accelerating to.

As described above, in the sensory inspection by humans, the defective mixture rate (defective outflow rate) of the shadow mask having defective chipping at the time of shipment of the shadow mask is as high as 300 ppm, which causes a problem in the sensory inspection method by humans. ing.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for automatically detecting a defective defective portion without performing a sensory test by a human for a defective unevenness, and to prevent the defective outflow. is there.

[0014]

According to a first aspect of the present invention, a defect of a shadow mask in which a large number of through holes having a predetermined size are formed is inspected according to a predetermined arrangement in a metal material of a thin film. In the inspection method for shadow mask,
(A) In advance, in the operation procedure of the stage, necessary stop position, instruction of the position of the next movement destination, registration of the above-mentioned position coordinates by design values, and in the image acquisition procedure, the image acquisition area and the photographing , The step of registering the reflection and transmission of illumination, (b) the step of previously registering the unit of the data address, the unit of the segment address, and the threshold range according to the inspection standard, and (c) the stage. A step of placing an object to be inspected at a predetermined position, and (d) movement of the stage using a stage driving method according to a predetermined procedure registered in advance,
A step of repeating the stop, (e) a step of repeating the image capturing by using the operation method of the CCD camera according to a predetermined procedure of registration in advance when the stage is stopped, and (f) an image processing method according to a predetermined procedure of registration in advance, By comparing with the surrounding through-holes, the contrast ratio of the through-holes is within a predetermined range A (a range where the through-holes are defective (a large hole defect), and all outside the range is good through-holes) The hole diameter is within the specified range R
(In the range where the through hole is defective (small hole defect), all outside the range is good through hole), or within a predetermined range Q (In the range where the through hole is defective (hole size defect), outside the range) If all the through holes are good), the step of extracting the through holes is performed. (G) If the contrast ratio of the through holes to be extracted is within a predetermined range A, the position coordinate value of the through hole and the defective item name hole size are set. If the hole diameter is within a predetermined range R, the coordinate value of the position of the through hole and the defective item name hole small are added, or if the hole diameter is within the predetermined range Q, the position of the through hole. A step of recording the coordinate values and the defective item name hole size, and (h) binarizing the image of the through hole to be extracted in data address units by using an image processing method according to a predetermined procedure registered in advance. And (i) using an image processing method according to a predetermined procedure of registration in advance. A step of binarizing processing by the segment address basis, by a predetermined procedure registered in advance (j),
Processing in parallel using at least two or more algorithm processing methods; (k) determining failure of results processed using a method according to a predetermined procedure registered in advance; A shadow mask inspection method comprising a step of assigning a name of a portion that is determined to be rejected as an inspection object as defective and selecting as a chip defect.

According to a second aspect of the present invention, there is provided a shadow mask inspection apparatus for inspecting defects of a shadow mask in which a large number of through holes having predetermined dimensions are formed in a thin film metal material according to a predetermined arrangement. , (A) In advance, in the operation procedure of the stage, a necessary stop position, an instruction of the position of the next movement destination, and registration of the position coordinates by design values,
In the image capturing procedure, an image capturing area, a unit for registering an image capturing magnification and image capturing with reflected light of illumination or transmitted light, (b) a unit of data address in advance,
There are provided means for registering a range of threshold values according to segment address units and inspection standards, (c) means for placing an object to be inspected on a stage at a predetermined position, and (d) a stage driving method according to a predetermined procedure of registration in advance. Means for repeatedly moving and stopping the stage using (e) means for repeating imaging using a CCD camera operating method according to a pre-registered predetermined procedure when the stage is stopped, and (f) image according to a pre-registered predetermined procedure. By using the treatment method and comparing with the surrounding through holes, the contrast ratio of the through holes is within a predetermined range A (a range where the through holes are defective (a hole size defect), and all outside the range is good through holes). Or in the case where the diameter of the through hole is within a predetermined range R (a range where the through hole is defective (a small hole is defective), and all outside the range is a good through hole), or within a predetermined range Q (where the through hole is Range of defects (large hole) Bad) and good through holes outside the range), means for extracting the through hole, and (g) position coordinate value of the through hole if the contrast ratio of the through hole to be extracted is within a predetermined range A. And give the defective item name hole size,
Alternatively, when the hole diameter is within a predetermined range R, the coordinate value of the position of the through hole and the defective item name hole small are given, or when the hole diameter is within the predetermined range Q, the coordinate value of the position of the through hole is Means for giving a defective item name hole size and recording, and (h) means for binarizing the image of the through hole to be extracted by a data address unit by using an image processing method according to a predetermined procedure of registration in advance. (I) A means for performing binarization processing in segment address units using an image processing method according to a predetermined registration procedure in advance, and (j) Parallel using at least two or more algorithm processing methods according to a predetermined registration procedure in advance. And (k) means for determining rejection of the result of processing using a method according to a predetermined procedure of registration in advance,
(L) A shadow mask inspection apparatus, comprising: a unit for assigning a name of a portion determined to be unsuccessful to an object to be inspected as defective chipping and selecting.

According to a third aspect of the present invention, there is provided a shadow mask inspection program for inspecting defects of a shadow mask in which a large number of through holes having predetermined dimensions are formed in a metal material of a thin film according to a predetermined arrangement. , (A) In advance, in the operation procedure of the stage, the necessary stop position, the instruction of the position of the next movement destination, the registration of the position coordinates by the design value, and the image capture area in the image capture procedure,
A program for registering photographing magnification and reflection / transmission of illumination, (b) a program for registering a unit of a data address, a segment address unit and a threshold range according to an inspection standard in advance, and (c) a target on the stage. A program for placing an inspection object at a predetermined position, (d) a program for repeatedly moving and stopping the stage using a stage driving method according to a predetermined procedure for registration, and (e) a predetermined registration for stopping the stage. The contrast ratio of the through-hole is determined by comparing the peripheral image with the through-hole using a program that repeats imaging using the CCD camera operating method according to the procedure and (f) an image processing method according to a predetermined procedure that is registered in advance. Within range A
(In the range where the through hole is defective (large hole defect), all outside the range is good through hole), or the hole diameter of the through hole is within a predetermined range R (range where the through hole is defective (small hole) Bad)
Then, if the outside of the range is all good through holes) or within a predetermined range Q (the range where the through holes are defective (the size of the hole is bad) and all the outside is good through holes), then the through holes are extracted. (G) If the contrast ratio of the through hole to be extracted is within the predetermined range, the position coordinate value of the through hole and the defective item name hole size are given, or if the hole diameter is within the predetermined range, A program for adding and recording the coordinate value of the position of the through hole and the defective item name hole small, or when the hole diameter is within a predetermined range Q, adding the coordinate value of the position of the through hole and the defective item name hole large And (h) a program for binarizing an image of the through hole to be extracted by a data address unit by using an image processing method according to a predetermined pre-registered procedure, and (i) image processing according to a predetermined pre-registered procedure. Method by segment address unit And a program for binarizing processing that,
(J) A program that is processed in parallel by using at least two or more algorithm processing methods according to a predetermined registration procedure in advance, and (k) Failure of the result of processing using the method according to a predetermined registration procedure Is a shadow mask inspection program, and (l) is a shadow mask inspection program including a program for selecting a portion of an object to be inspected, which has been determined to be rejected, as a chip defect.

According to a fourth aspect of the present invention, there is provided a stage device 25 for mounting a shadow mask of an object to be inspected, which is operated by the stage driving means 18 in the X direction 14, the Y direction 15 and the θ rotation direction 16. , A plurality of pillars 33 standing upright on a pedestal 32 supporting the stage device at positions facing the upper surface of the stage 19, an image pickup device 24 by a CCD camera 20 attached, data or work order instruction means 28, and length measurement. 29 means for performing, and 30 means for performing image processing,
System control device 26 including processing 31 means by algorithm and 27 means for controlling the whole
A shadow mask inspection program, comprising: a shadow mask inspection program according to claim 3 for controlling the operation of the control means.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A detailed description will be given below along with embodiments of the present invention.

FIG. 1 is a partial perspective side view showing an embodiment of the inspection apparatus of the present invention.

As shown in FIG. 1, the shadow mask inspection apparatus for inspecting defects of the shadow mask according to the present invention comprises a stage device 25, an image pickup device 24, and a system control device 26.

First, the stage device 25 is a stage (table) on which the shadow mask 1 of the inspection object is placed.
And a stage drive means 18 for driving the stage 19. The stage 19 is driven 14 in the X direction, driven 15 in the Y direction, and rotated 16 in the θ direction by means of a stage driving unit 18. That is, in order to finely adjust the mounted inspection object 1 to a predetermined position on the stage 19, first, the tilt is corrected by the adjustment movement of the rotation 16 in the θ direction. Next, the drive adjustment movement in the X direction 14 and the Y direction 15 is performed, and the position is corrected so that the inspection object 1 comes to a predetermined position.

The stage device 25 is repeatedly moved and stopped in accordance with the previously registered stage operation procedure.

Next, the image pickup device 24 includes a stage device 25.
The CCD camera 20 or the line sensor as the photographing means, the operation means 22 for operating the CCD camera 20 or the line sensor, and the imaging means at the positions facing the upper surface of the stage of the plurality of columns 33 standing on the pedestal 32 supporting the 23 and. In order to take an image of the object 1 to be inspected, the magnification of photographing is set to a predetermined magnification in advance.

Further, in accordance with a pre-registered image capturing procedure, the image capturing area, switching of irradiation conditions such as transmitted light or reflected light, and the operation of the stage using the image capturing means 23 of the imaged data are interlocked with each other. Repeat the work of capturing images.

Next, the system control device 26
The hardware device includes a data or work order instruction means 28, a length measurement means 29, an image processing means 30, an algorithm processing means 31, and a means 27 for controlling the entire inspection apparatus. The means 27 for controlling the entire inspection apparatus uses data storage, data storage for inputting / outputting data, a desk memory storing the program of the present invention, a processor, an operating system (OS), and the program of the present invention. Control the operation of the entire device.

The data or work order instructing means 28 gives an instruction or registration, confirmation on the screen, and the like. The means 29 for measuring the length measures the diameter of the through hole, and means 30 for image processing.
Converts the captured image including the measurement of the contrast ratio into data or the like.

Next, processing means 31 based on an algorithm
Using the algorithm of the present invention, for example, by utilizing an automatic calculation function by a computer such as an extraction method based on an image area ratio, a method of measuring an image length, a method of feature extraction, or the like. In order to guarantee the detection accuracy of defect and defect, we adopted a process of making a comprehensive judgment using multiple algorithms.

The adoption of the process of making a comprehensive judgment using the above-mentioned plurality of algorithms has a drawback that the number of man-hours for the arithmetic processing increases, so that the processing of the plurality of algorithms is performed by using hardware equipment such as a personal computer. We adopted a method to execute processes concurrently in parallel.

Next, the content of the present invention will be described in detail with reference to the accompanying drawings.

8A and 8B are pattern screens of the confirmation screen of the inspection device for the normal through hole of the shadow mask, and FIG. 8A shows the transmitted light. Further, (b) is a screen by reflected light. Next, (d) is a side sectional view of a normal through hole, (c) is a plan view of transmitted light, and (e) is a plan view of reflected light. (D) is a cross-sectional view of the through hole, and the correlation between the edge portions and the boundary line of the plan views (c) and (e) is indicated by dotted lines in the drawing.

Further, the drawing shown in FIG. 9 is an example of defective chipping of a through hole, and is a pattern screen of a screen obtained by reflected light emitted from an inspection apparatus and reflected. (A) is an example of a defective chip with a large hole, and (b) is a screen showing an example of a defective chip with a small hole. (C) shows a side sectional view of a defective portion of a chip having a large hole. The dotted line in (c) shows a normal cross-sectional shape,
(C) shows a greatly etched shape.
(D) is a side sectional view of a defective part of a chip with a small hole, (d)
The dotted line in the middle shows the normal cross-sectional shape, and (d) shows the shape of the etching residue.

Next, detailed steps of the shadow mask inspection described in the above claims will be described.

In order to control the production of the shadow mask, important quality data is determined according to the production specification using the product type number as a code. Data and the like are registered in advance in the inspection device according to the determined quality data.

The procedure of the present invention will be described below in (a) to (l). (A) In order to inspect the entire surface of the object 1 to be inspected in advance, in a stage operation procedure, the necessary stop position, the instruction of the position of the next movement destination, and the above-mentioned position coordinates by design values are registered. Register the procedure for moving the stage. Next, in the image capturing procedure, the image capturing area, the photographing magnification, and the reflection / transmission of illumination are registered.

(B) The minimum unit of the data address is registered in advance, and the multi-gradation data photographed by the CCD camera is binarized by the unit of 0 or 1 of the unit of the data address to make a bit map. Data processing by. Input the data address unit in μm.

The minimum unit of the segment address unit S is registered, and the method is registered by the relational expression (1) with the unit D of the data address. S = N * D ――――――――― (1) N; Integer

Next, the threshold range is registered with reference to the inspection standard.

(C) In the step of mounting the inspection object on the stage at a predetermined position, the inspection object 1 to be mounted is placed on the stage 1
In order to finely adjust to a predetermined position of 9, the tilt is first corrected by the adjustment movement of the rotation 16 in the θ direction. Then X direction 1
4, the position of the object to be inspected 1 is corrected to a predetermined position by the drive adjustment movement in the Y direction 15.

(D) The stage is repeatedly moved and stopped in accordance with the previously registered stop position of the stage and its position coordinates, and the next destination and its position coordinates.

(E) When the stage is stopped, the image pickup area which is registered in advance, the photographing magnification of the CCD camera, the reflection of the illumination, and the transmission method are used to repeat the photographing.

(F) By using an image processing method according to a predetermined procedure registered in advance, the contrast ratio of the through hole is determined by comparison with the average value of the six surrounding through holes closest to the through hole. In the range A, or in the case where the diameter of the through hole is within the predetermined range R or within the predetermined range Q, the through hole is extracted.

(G) When the contrast ratio of the through hole to be extracted is within the predetermined range A, the position coordinate value of the through hole and the defective item name hole size are given, or when the hole diameter is within the predetermined range R. The position of the through hole is recorded by giving the coordinate value and the defective item name hole small, or when the hole diameter is within a predetermined range Q, the position of the through hole and the defective item name hole large are given. To do. Here, A is a range where the through hole is defective (a large hole defect), all outside the range are good through holes, and R is a range where the through hole is defective (small hole defect) and all outside the range is good. Through-holes and Q are ranges where the through-holes are defective (hole-sized defects), and all outside the range are good through-holes.

(H) The image of the through hole to be extracted is converted into a data address unit by using a predetermined conversion algorithm in order to convert the data into a bit map by using the image processing method of the data address unit (D) registered in advance. Binarize.

(I) Using the image processing method, the image of the bit map of the data address unit is binarized in advance by the segment address unit according to the relational expression (1) of registration using a predetermined conversion algorithm.

(J) In accordance with a predetermined procedure of registration in advance, for example, a processing method for comparing the area of the putter portion and the transparent portion for each segment area, a processing method for comparing the shape of a pattern diagram with bitmap data for each segment, In the above pattern diagram, the segment unit is changed in accordance with a certain rule, the dimension comparison is performed by the change in the shape, the outer and inner contour lines 34 and 35 are extracted by the data conversion method, and the like. The process of the algorithm capable of extracting the defective chip of the through hole is performed in parallel at the same time by using at least two or more algorithm processing methods.

(K) The result of processing is determined in advance by using a method according to a predetermined registration procedure. As a result of the processing of the above algorithm, a plurality of outputs are output at the same time, and if the output data are all non-defective products, it is judged as non-defective product, and other than that, all are judged as defective chips, and based on the judgment method, the optimum judgment in accordance with the case Adopt the method.

(L) If the result of the above judgment is defective, a defective mark indicating that the inspection object is defective due to chipping is printed and selected from the lot. It is possible to provide an inspection apparatus that employs a step of automatically extracting and selecting a defect of chipping of a through hole by the above-described inspection method for a shadow mask.

FIG. 2 is a process chart for explaining a method of converting pattern data of a minimum unit (data address unit) in order to convert a multi-gradation image photographed by a CCD camera into data. Image processing is performed on the partial image. That is, a smoothing process for removing noise in an image, a binarizing process for converting multi-tone data into binary data consisting of 0 or 1, and an edge extracting process for extracting a boundary between a pattern and a background portion. And the thinning process of contracting until the width of the image of the line having the thickness becomes 1 or the minimum unit of the image data. By these processes, it is possible to extract the contour line that connects the boundary between the light-shielding portion and the transmissive portion of the pattern portion.

FIG. 3 is a diagram for explaining a method of converting an image photographed by a CCD camera from a minimum unit (data address unit) of bitmap pattern data into a segment address unit in the order of steps. FIG. 3A shows an image of multi-tone data captured by reflected light. (B) shows a pre-process of dividing into a map for each data address, and the image is a schematic diagram in which an image of multi-tone data is overlaid.
FIG. 3C shows a binarized bit map diagram in which the boundary line of the image is adjusted according to a certain rule. Next, FIG.
(D) shows a schematic diagram in which an image of bitmap data in data address units is overlaid in order to divide into a map in segment address units. FIG. 3E is a schematic diagram in which the area ratio (%) of the data value 1 or the area ratio (%) of the data 0 value is described in each segment frame in each segment unit.

Next, FIGS. 4 (a) to 4 (c) are diagrams illustrating a method of processing the automatic extraction of abnormal points by the automation processing in the order of steps. By changing the segment unit and changing the binarized data of the segment and comparing the shapes of the through holes in the periphery, the defect size of defective chips is measured and the result is output.

FIG. 5 is a diagram for explaining a method of performing a vector data conversion process for converting a contour line of a pattern into vector data in the order of steps. From the starting point of the contour line of the pattern, vectors having the same size components are sequentially arranged in the direction along the contour line, and vectors having quantities and directions are connected to convert the vector data to the end point of the contour line. Figure 5 here
(A) is a top view showing the outline of the outer side of a through-hole.
FIG. 5B shows a result of data obtained by converting the outer contour line into vector data. FIG. 5C shows the reference vector and the relative angle θ between each vector. FIG. 5D shows a difference between adjacent angles θn of each vector, (| θn-θn-1 |)
Is shown in the graph, and it can be seen from the graph that there is a peculiar feature that has an almost constant angle that changes gently.

[0052]

In the inspection process for detecting a defective chipped portion having a defective shape in the hole wall of the through hole, conventionally, the selection by the sensory inspection method by a person is changed to the selection by the automatic inspection by the apparatus of the present invention.

[0053]

EXAMPLES Next, examples showing an example of the present invention will be described.

Example 1 A test assuming the inspection apparatus of the present invention was conducted using one sheet of shadow mask that passed the inspection. The through holes in the sheet were inspected and measured. The inspection method is to compare the total irradiation energy amount of the transmitted light that has passed through the openings of each through-hole with the contrast value based on the relationship of the density of the imaging and the average measurement value of the six through-holes close to the periphery. Did. The above value was defined as the contrast ratio. The through-holes arranged in one sheet are designed so that the planar shape and the cross-sectional shape of the central portion and the peripheral portion of the sheet are gently changed. The comparison in the area of holes approximated the through holes of the same shape. Further, the data of the range of the distribution of the contrast ratio of all the through holes in the sheet was stored in the database, the number of samples was increased, and the lower limit value and the upper limit value of the database were used as a reference for the standard value.

Next, using one sheet of defective shadow masks having a plurality of defective through holes formed as test products, a test assuming the inspection apparatus of the present invention was conducted. The arranged defective through-holes are test products that reproduce a possible defective shape. The through holes in the sheet were inspected and measured. As the inspection method, the major axis diameter and the minor axis diameter of the through hole were measured using the dimension measurement by reflected light and the dimension measurement on the contour line extracted by the data processing. The quality of the through-holes and the criteria for the defectives are determined by registering the data by referring to the lower-to-upper dimension of the distribution of the measured values of the through-holes of the non-defective shadow masks in the past, and by judging the conditions based on the threshold value. Defective through holes could be reliably detected.

The defect of chipping of the through hole of the present problem is caused by the abnormality associated with the cross-sectional shape of the through hole causing all the chipping defects. Therefore, the contrast ratio of the through-hole is within a predetermined range A (range in which the through-hole becomes defective (hole-sized defect)
In the case of all the through holes outside the range, the position coordinate value of the through hole and the defective item name hole size are given, or the hole diameter is within a predetermined range R (range where the through hole is defective (small hole size). In the case of (the defect of No.) and all of the outside of the range are good through holes), the coordinate value of the position of the through hole and the defective item name small hole are given, or the hole diameter is within a predetermined range Q (the through hole becomes defective). In the case of a range (defective hole size) and all outside the range being good through holes, the coordinate value of the position of the through hole and the bad item name hole size are given and recorded. In the range A, the range R, and the range Q, safety factors are taken into consideration so that products with anxiety can be extracted.
We adopted a method to narrow the range of non-defective products.

It is important to improve the accuracy of extraction of defective through-holes by the above inspection and to detect them reliably. Further, at the time of inspection, it was possible to automatically inspect as a defective chip by reinspecting the inside of the cross section of the through hole according to the position coordinates of the defective through hole.

The automatic extraction of the above chip defects was performed by the method shown in FIG. That is, the algorithm of the present invention is a method in which data is divided into areas in segment units, areas of the transmissive portion and the reflective portion of each area are calculated, and a defective portion is extracted by condition determination based on a predetermined threshold value.

The above-described chipping defect was automatically extracted by the method shown in FIG. That is, the algorithm of the present invention employs a method of extracting a defective portion of chipping of the through hole by making a determination by comparing images in bitmaps of segment units. For example, as shown in FIGS.
This is an example of the defect shape when the maximum size of the defective shape of the defective part of the chip registered in the inspection standard is 20 μm, and the method for measuring the maximum size will be specifically described. Further, the segment unit is changed stepwise such as 5 μm, 10 μm, and 20 μm, but the minimum value of the segment unit is preferably half the maximum dimension value of the defect shape. Therefore, in this case, the minimum unit is 10 μm, and the process in units of 5 μm is useless.

The above-mentioned chipping defect was automatically extracted by the method shown in FIG. That is, the algorithm of the present invention employs a method in which the vectorization processing is performed from the contour of the through hole and the feature of the change in the relative angle of each vector is utilized.
Further, for the component of the magnitude of each vector, half of the maximum dimension value of the defect shape is suitable for the same reason as described above.

The extraction of chip defects by the above algorithm adopts a method of simultaneously processing a plurality of processes in parallel, so that a plurality of processed data are output. A system for guaranteeing the accuracy of extraction was adopted by adopting a method of making a comprehensive judgment based on the above results. Only when all the outputs were judged to be non-defective, the result was passed, and otherwise the chip was defective.

In the above-mentioned parallel processing, since the necessary inspection data uses the image pickup data obtained by the CCD camera, the device for fetching the data and the device for arithmetically processing the data by the algorithm or the device for judging the result are operated separately. It is possible to expect the effect of improving the operation rate of the inspection device for inspecting the product. Also in terms of inspection cost, there is an effect that the inspection cost does not increase even if the number of algorithms to be processed for parallel processing of the algorithms increases.

[0063]

By using the inspection apparatus of the present invention, it is possible to provide a shadow mask inspection method capable of reliably and automatically detecting defective defects of a shadow mask defect with high precision.

[Brief description of drawings]

FIG. 1 is a partial perspective side view of a shadow mask inspection apparatus of the present invention.

FIG. 2 is a process of binarization processing of a minimum unit of data address and a process of extracting the contour thereof, (a) is a pattern diagram of multi-tone through holes, and (b) is a through hole by a binarized bitmap. 2C is a contour diagram of a pattern of through holes.

FIG. 3 is a conceptual diagram showing an embodiment for processing data of a pattern diagram of through holes, in which (a) is a plan view of reflected light;
(B) is a plan view in which area divisions in data address units are superimposed on a partially enlarged view, (c) is a pattern diagram by a binarized bitmap, and (g) is 2 in each segment unit.
It is a bit map of binarization, (d) is a segment area, (e) is a data value 1 and 0 in each segment.
And (f) is a conceptual diagram illustrating a rule of binarized data given to each segment.

FIG. 4 is a conceptual diagram showing an embodiment for processing data of a pattern diagram of through holes, (a) is a bitmap pattern diagram of a data address unit of 1 μm, and (b) is a partially enlarged view of non-defective through holes. , (C) a partially enlarged view of the through hole with defective chipping,
(D) is a difference figure between the pattern figures (b) and (c),
The segment units of (b) to (d) are 5 μm, 10 μm, 2
It is a conceptual diagram explaining the case changed to 0 μm.

5A and 5B are conceptual diagrams showing an embodiment for processing data of a through hole pattern diagram, FIG. 5A is a bitmap data pattern diagram, FIG. 5B is a contour line extracted from the through hole, and FIG.
Is a vector conversion, and (d) is a graph showing a difference in relative angle between adjacent vectors.

FIG. 6 is a plan view of a shadow mask in the conventional shadow mask portion, (a) is a perspective side view of a through hole,
(C) is a sectional side view.

FIG. 7 is a side sectional view of a through hole of a conventional shadow mask,
(A) is a non-defective product, (b) is a defect with a large hole, and (c) is a partial side sectional view of a defect with a small hole.

FIG. 8 is a partial pattern diagram showing a state of a normal through hole on a screen of the inspection device, (a) is a pattern diagram of transmitted light, (b) is a pattern diagram of reflected light, and (c) is a transmitted light plane. Figure, (e)
Is a plan view of reflected light, and (d) is a side sectional view.

FIG. 9 is a partial pattern surface showing a state of defective through holes on a screen of the inspection apparatus, wherein (a) and (b) are plan views of reflected light due to defective chips, and (c) and (). d) is a side sectional view.

[Explanation of symbols]

1 ... Shadow mask (object to be inspected) 2 ... Large hole (defective) 3 ... Small hole (defective) 4 ... Chip (defect) that is locally excessively etched to the material region 5 ... Local in through-hole region 6) Defects that are excessively etched (defective) 6 ... Blemish (defective) 7 ... Mura (defective) 8 ... Thin film metal material (shadow mask material) (metal material) 9 ... Through hole (predetermined size) Through hole) (passes the dimensional standard) 10 ... Through hole arrangement area 11 ... Boundary line 12 between through hole and metal material surface ... Image 13 by transmitted light beam ... Image 14 by reflected light beam ... Stage drive in X direction 15 ... Stage drive in Y direction 16 ... Rotation drive in θ direction 17 ... Clamp 18 for mounting an object to be inspected ... Stage driving means 19 ... Stage (table) 20 ... CCD camera, line sensor 21 ... Camera operation 22 ... Camera of Bright operation means 23 ... Imaging means 24 ... Imaging device 25 ... Stage device 26 ... System control device 27 ... Control system 28 ... Input screen 29 ... Length measurement system 30 ... Image data processing system 31 ... Algorithm processing system 32 ... Pedestal 33 ... Plural Pillar 34 ... Outer contour line 35 ... Inner contour line

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) G06T 7/00 150 G06T 7/00 150 5C027 H01J 9/14 H01J 9/14 G 5L096 H 9/42 9/42 AF term (reference) 2F065 AA49 BB18 CC00 FF04 JJ02 JJ03 JJ26 PP12 QQ04 QQ08 QQ31 TT03 2G051 AA90 AB02 AC21 CA03 CA04 CB01 CB02 DA07 EA11 EA19 EB01 ED08 ED21 2G086 EE12 5B057 AA04 BA19 BA30 CA08 CA12 CB06 CB12 CE12 CH01 DA03 DB02 DB09 DC22 5C012 AA02 BE03 5C027 HH29 5L096 AA06 BA03 CA02 EA43 FA14 FA69 GA51 LA11

Claims (4)

[Claims] 1. A shadow mask inspection method for inspecting defects of a shadow mask in which a large number of through holes having predetermined dimensions are formed according to a predetermined arrangement in a thin metal material.
(A) In advance, in the operation procedure of the stage, necessary stop position, instruction of the position of the next movement destination, registration of the above-mentioned position coordinates by design values, and in the image acquisition procedure, the image acquisition area and the photographing , The step of registering the reflection and transmission of illumination, (b) the step of previously registering the unit of the data address, the unit of the segment address, and the threshold range according to the inspection standard, and (c) the stage. A step of placing an object to be inspected at a predetermined position, and (d) movement of the stage using a stage driving method according to a predetermined procedure registered in advance,
A step of repeating the stop, (e) a step of repeating the image capturing by using the operation method of the CCD camera according to a predetermined procedure of registration in advance when the stage is stopped, and (f) an image processing method according to a predetermined procedure of registration in advance, By comparing with the surrounding through-holes, the contrast ratio of the through-holes is within a predetermined range A (a range where the through-holes are defective (a large hole defect), and all outside the range is good through-holes) The hole diameter is within the specified range R
(In the range where the through hole is defective (small hole defect), all outside the range is good through hole), or within a predetermined range Q (In the range where the through hole is defective (hole size defect), outside the range) If all the through holes are good), the step of extracting the through holes is performed. (G) If the contrast ratio of the through holes to be extracted is within a predetermined range A, the position coordinate value of the through hole and the defective item name hole size are set. If the hole diameter is within a predetermined range R, the coordinate value of the position of the through hole and the defective item name hole small are added, or if the hole diameter is within the predetermined range Q, the position of the through hole. A step of recording the coordinate values and the defective item name hole size, and (h) binarizing the image of the through hole to be extracted in data address units by using an image processing method according to a predetermined procedure registered in advance. And (i) using an image processing method according to a predetermined procedure of registration in advance. A step of binarizing processing by the segment address basis, by a predetermined procedure registered in advance (j),
Processing in parallel using at least two or more algorithm processing methods; (k) determining failure of results processed using a method according to a predetermined procedure registered in advance; A method for inspecting a shadow mask, which comprises a step of assigning a name of a portion determined to be rejected to an inspection object as defective chipping and selecting. 2. A shadow mask inspection apparatus for inspecting defects of a shadow mask in which a large number of through holes having predetermined dimensions are formed in a thin metal material in a predetermined arrangement.
(A) In advance, in the operation procedure of the stage, necessary stop position, instruction of the position of the next movement destination, registration of the above-mentioned position coordinates by design values, and in the image acquisition procedure, the image acquisition area and the photographing And (b) means for registering a unit of a data address, a segment address unit and a threshold value range according to an inspection standard in advance, and (c) A means for placing an object to be inspected on a stage at a predetermined position; (d) a means for repeatedly moving and stopping the stage by using a stage driving method according to a predetermined procedure registered in advance; By comparing the means for repeating the imaging using the operation method of the CCD camera according to the predetermined procedure of registration and (f) the image processing method according to the predetermined procedure of registration in advance, by comparing with the surrounding through holes. When the contrast ratio of the through hole is within a predetermined range A (when the through hole is defective (a large hole defect) and all outside the range is good through hole), or when the through hole has a hole diameter within a predetermined range R (In the range where the through hole is defective (small hole defect), all outside the range is good through hole), or within a predetermined range Q (In the range where the through hole is defective (hole size defect), outside the range) If all the through holes are good), the means for extracting the through holes is used. (G) If the contrast ratio of the through holes to be extracted is within a predetermined range A, the position coordinate value of the through hole and the defective item name hole size are set. If the hole diameter is within a predetermined range R, the coordinate value of the position of the through hole and the defective item name hole small are added, or if the hole diameter is within the predetermined range Q, the position of the through hole. Means for recording with the coordinate values of and the defective item name hole size, and (h) a predetermined hand of registration in advance. A method of binarizing an image of a through hole to be extracted by a data address unit by using the image processing method according to (1), and (i) binarization by a segment address unit by using an image processing method according to a predetermined procedure registered in advance. Processing means, (j) processing in parallel using at least two or more algorithm processing methods according to a predetermined registration procedure, and (k) processing using a method according to a predetermined registration procedure A means for judging the failure of the result, and (l) a means for selecting the name of the portion of the object to be inspected, which is judged to be defective, as a chip defect, and selecting
Inspection device for shadow masks. 3. A shadow mask inspection program for inspecting defects of a shadow mask in which a large number of through holes having predetermined dimensions are formed according to a predetermined arrangement in a thin-film metal material. In the procedure, the necessary stop position, the indication of the position of the next movement destination, the registration of the position coordinates by the design value, and the image capturing procedure,
Image capture area, magnification of shooting and reflection / transmission of illumination,
(B) a program for registering a data address unit, a segment address unit and a threshold range according to the inspection standard in advance, and (c) an object to be inspected is placed at a predetermined position on the stage. Program and (d)
A program for repeatedly moving and stopping the stage by using a stage driving method according to a predetermined procedure registered in advance, and (e)
A program that repeats imaging using a CCD camera operating method according to a predetermined procedure registered in advance when the stage is stopped,
(F) By using an image processing method according to a predetermined procedure registered in advance, the contrast ratio of the through hole is within a predetermined range A by comparison with the surrounding through hole (range in which the through hole is defective (large hole defect) ), All outside the range is good through hole), or the diameter of the through hole is within a predetermined range R (range where the through hole is defective (small hole defect), and all outside the range is good through hole) ,
Alternatively, in the case of Q within a predetermined range (a range where a through hole is defective (a hole size defect) and all outside is a good through hole), a program for extracting the through hole, and (g) a through hole to be extracted If the contrast ratio is within the predetermined range, the position coordinate value of the through hole and the defective item name are given, or if the hole diameter is within the predetermined range, the coordinate value of the through hole position and the defective item name. A program for adding and recording a coordinate value of the position of the through hole and a defective item name hole size when the hole size is within a predetermined range Q, and (h) a predetermined procedure of pre-registration A program for binarizing an image of a through hole to be extracted by a data address unit by using the image processing method according to (1), and (i) Binarization by a segment address unit by using an image processing method according to a predetermined procedure registered in advance. The program to process, By a predetermined procedure j) previously registered,
A program for processing in parallel using at least two or more algorithm processing methods, (k) a program for determining rejection of the result of processing using a method according to a predetermined procedure registered in advance, and (l) An inspection program for a shadow mask, comprising a program for assigning a name of a portion determined to be rejected to an inspection object as defective chip and selecting the defective portion. 4. A stage device for mounting a shadow mask of an object to be inspected, which is moved in the X direction, Y direction, and θ rotation direction by a stage driving means, and a plurality of standing devices standing on a pedestal supporting the stage device. An image pickup device with a CCD camera attached at a position facing the upper surface of the stage of the column
Data or work order instruction means, length measuring means,
Image processing means, algorithm processing means,
4. A shadow mask inspection program, comprising: a system control device having a means for controlling the entire device; and the shadow mask inspection program according to claim 3, which controls the operation of the control means.