JPH11312242A - Inspecting situation displaying method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To confirm an inspecting situation in real time. SOLUTION: A work image 1 similar to that of an inspection work is displayed on the inspecting situation displaying image of a display. Each mark 3 to 5 is displayed in a different color for each inspecting situation at a position on a work image corresponding to a presently inspected area on an inspection work. The mark 3 is displayed for an area under image inspection, the mark 4 for an area under first inspection and the mark 5 for an area under second inspection. When a defect is detected within an inspecting area, an NG mark 6 is displayed at a position on the work image, corresponding to the position of the defect within the inspecting area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for automatically inspecting an inspection work by photographing the inspection work with a camera, and more particularly to an inspection status display method for displaying an inspection status of the inspection work.

[0002]

2. Description of the Related Art Conventionally, PGA (Pin Grid Array) has been known as a mounting technique suitable for a demand for increasing the number of pins of ICs and LSIs. In PGA, a ceramic substrate is used as a base of a package for attaching a chip, and wiring is performed to a lead wire extraction position. To make this ceramic substrate, a so-called green sheet made by kneading alumina powder with a liquid binder is used, and a paste containing a high melting point metal is screen-printed on the green sheet. By stacking and firing the required number of such sheets, so-called simultaneous firing, in which the green sheets are sintered and the paste is metallized, is performed.

In such a green sheet, a pattern is visually inspected by a human using a microscope after the pattern is formed. However, a technique for automatically inspecting a pattern formed on a green sheet or the like by using a TV camera has been proposed, because skill is required to visually inspect a fine pattern and the eyes are heavily used. For example,
JP-A-6-273132, JP-A-7-11086
No. 3).

FIGS. 6 and 7 are diagrams for explaining a conventional inspection method for detecting a disconnection described in Japanese Patent Application Laid-Open No. 6-273132. A master pattern created by imaging the pattern to be measured determined as a non-defective product is registered as a set of straight lines indicating pattern edges. The pattern to be measured is input as a set of edge data (edge coordinates) indicating a pattern edge extracted from a grayscale image obtained by capturing the pattern. Then, the extracted edge data n1, n2, n3,... Of the pattern to be measured are associated with the straight lines of the master pattern. In order to perform this association, as shown in FIG. 6, the bisectors A2 ', A3', which divide the angles formed by the continuous straight lines A1 and A2, A2 and A3.・ ・

.. Are divided into areas respectively belonging to the straight lines A1, A2, A3... In the master pattern by the bisectors A2 ′, A3 ′. .. Exist in each area are associated with the straight lines A1, A2, A3,... Of the master pattern to which the area belongs. . For example, in FIG. 6, the edge data n1 to n3 are associated with the straight line A1, and the data n4 to n6 are associated with the straight line A2. Next, the edge data of the pattern to be measured is compared with the master pattern to check whether the pattern to be measured is disconnected.

This inspection is realized by a labeling process for tracing a pattern edge by tracing connected edge data n1 to n9 of a pattern to be measured, as shown in FIG. At this time, since the edge data is not connected at the disconnected portion due to the disconnection generated at the leading end of the pattern to be measured, there is no edge data corresponding to the straight lines A3 to A5 of the master pattern. Thus, the disconnection of the pattern to be measured can be detected.

FIG. 8 is a diagram for explaining a conventional inspection method for detecting a short circuit described in JP-A-6-273132. First, in the inspection area 20 in which the master pattern and the pattern to be measured are cut out to a predetermined size, the connected edge data of the pattern to be measured is tracked. Thereby, each edge data of the pattern to be measured is n1 to n1.
8 and are sequentially labeled. However, the edge data n8 and n17 are not registered in the master pattern Mb composed of two opposing straight lines similarly to the master pattern Ma composed of two opposing straight lines indicating a pattern edge. Thus, a short circuit of the pattern to be measured can be detected.

FIG. 9 is a view for explaining a conventional inspection method for detecting a defect or a projection described in Japanese Patent Application Laid-Open No. 7-110883. First, a perpendicular line perpendicular to the center line L is drawn, and the length between intersections where the perpendicular line intersects the straight lines A1 and A2 indicating the edges of the master pattern is determined in advance as the width W0 of the master pattern. Next, in the actual inspection,
The distance between the facing edge data is obtained by lowering the perpendicular to the center line L of the master pattern from the edge data n of the pattern to be measured. This is the width W of the pattern to be measured, and the loss or protrusion of the pattern to be measured is detected by comparing this with the width W0 of the master pattern.

However, in the pattern inspection apparatus using such an inspection method, there is a problem that the pattern inspection takes a long time because a detailed inspection by comparison with the master pattern is performed by software over the entire pattern to be measured. . Therefore, a pattern inspection apparatus capable of performing inspection in a short time has been proposed (Japanese Patent Application No. 8-302807).
issue). In the pattern inspection apparatus disclosed in Japanese Patent Application No. 8-302807, a defect candidate of a measured pattern is detected by hardware (primary inspection), and only a predetermined small area including the detected defect candidate is inspected by software. Secondary inspection), it is possible to inspect the defect of the pattern to be measured at a higher speed than before. However, in any of the above-described pattern inspection apparatuses, the inspection result is only displayed after the inspection is completed, so that the inspection status that is constantly changing, such as the position of the inspection area and the type of the inspection being executed, is checked during the inspection. It is not possible.

[0010]

As described above, the conventional pattern inspection apparatus has a problem that the inspection status cannot be confirmed during the inspection. The present invention has been made to solve the above problems, and has as its object to provide an inspection status display method capable of checking an inspection status in real time.

[0011]

According to the inspection status display method of the present invention, a work image corresponding to an inspection work is displayed on a screen of a display device, and the inspection on the inspection work is performed. A mark representing the inspection status of the inspection area is displayed at a position on the work image corresponding to the inspection area as an execution unit. By displaying the mark indicating the inspection status of the inspection area at the position on the work image corresponding to the inspection area, the current inspection status can be easily known. According to a second aspect of the present invention, a frame-like mark indicating the outer edge of the inspection area is displayed as the mark indicating the inspection status, and the line type is changed for each inspection status. . Claim 3
As described above, a frame-like mark indicating the outer edge of the inspection area is displayed as a mark indicating the inspection status, and is displayed in different colors for each inspection status.

[0012]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a pattern inspection apparatus showing an embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a green sheet serving as an inspection work;
Reference numeral 12 denotes a piece that forms an independent pattern group formed on the green sheet 11, 13 denotes an XY table on which the green sheet 11 is placed, 14 denotes a line sensor camera that captures an image of the green sheet 11, and 15 denotes a defect candidate of the pattern to be measured. A first image processing apparatus that outputs address information indicating the position of the defect candidate, and obtains an error between the measured pattern and the master pattern in a predetermined area including the defect candidate based on the address information. A second image processing device for inspecting the pattern to be measured, 17 is a host computer for controlling the entire device, and 18 is a display device for displaying the inspection status. On the green sheet 11, a horizontal N
Pieces 12 arranged in a matrix of pieces × M pieces (N and M are integers of 1 or more) are printed. Usually, the pieces 12 have the same pattern, and one piece is, for example, IC1.
Equivalent to an individual.

Next, the operation of such a pattern inspection apparatus will be described. First, a master pattern created before inspection will be described. Host computer 17
Is read out by a magnetic disk device (not shown), for example, green sheet design value data (hereinafter referred to as CAD data) created by a CAD (Computer Aided Design) system and written on a magnetic disk, for example. Then, pattern edge data is extracted from the read CAD data, and is used as a first master pattern serving as a reference for inspection. The extracted edge data of the first master pattern is a set of straight lines indicating pattern edges.

It is needless to say that the green sheet 11 is produced based on the CAD data and a pattern is printed on the sheet 11 by screen printing. Next, the host computer 17 creates a second master pattern for detecting loss or disconnection and a third master pattern for detecting protrusions or short circuits from the first master pattern as follows. FIG. 2 is a diagram for explaining a method of creating the second and third master patterns, and shows a part of the first master pattern.

First, as shown in FIG. 2A, the first master pattern is contracted in a direction perpendicular to its center line,
A second master pattern M1 is created. This is because opposing straight lines A1 and A1 indicating both edges of the first master pattern
4 (center line is L1) and the distance between A2 and A3 (center line is L2) are narrowed to narrow the first master pattern.

Subsequently, as shown in FIG. 2B, the first master pattern is expanded in a direction perpendicular to the center line to create a third master pattern M2. This corresponds to the opposite straight line A5 indicating both edges of the first master pattern.
And A8 (center line is L3), A6 and A7 (center line is L
4), A9 and A12 (center line is L5) and A10 and A1
1 (the center line is L6), and the first master pattern can be made thicker by widening the respective intervals.

However, actually, the third master pattern M2
Is a master pattern M composed of straight lines A5 to A8.
a and a region (base portion where no pattern exists) sandwiched between two patterns generated by expanding the master pattern Mb including the straight lines A9 to A12. The expansion and contraction processing is not performed on the positioning marks used for positioning with the pattern to be measured.

Next, the inspection of the pattern to be measured will be described. FIG. 3 is a diagram showing a state of the inspection status display screen of the display device 18. As shown in FIG. In FIG. 3, reference numeral 1 denotes a work image similar to the green sheet 11 displayed on the inspection status display screen of the display device 18, and 2 denotes a piece image corresponding to each piece 12. 3 (b) to 3 (g) show only one piece image 2 of the work image 1 corresponding to the inspection target piece. The host computer 17 is configured as shown in FIG.
As shown in (a), the work image 1 corresponding to the green sheet 11 is displayed on the display device 18. The work image 1 can be created based on the first master pattern described above.

The host computer 17 also stores the position of the pieces 12 on the green sheet 11 such as the number N of the pieces 12 in the horizontal direction, the number M of the pieces 12 in the vertical direction, and the interval between the pieces 12.
The inspection area in each piece 12 is registered in advance. At this time, the entire piece may be used as the inspection area, but in the present embodiment, the piece 12 is divided into three parts, each of which is used as the inspection area.

FIG. 4 is a diagram showing a flow of processing in the pattern inspection apparatus. In the present embodiment, a description will be given assuming that the first image processing device 15 can perform three processes in parallel. First, the host computer 17
Sets the image capture of the inspection area A of the inspection target piece to the first
3 and a mark 3 indicating that an image is being input is displayed at a position on the piece image 2 corresponding to the inspection area A on the inspection target piece (FIG. 3).
(B)). The mark 3 is, for example, a yellow frame indicating the outer edge of the inspection area A.

The first image processing device 15 includes a line sensor camera 1 set on the inspection area A of the inspection target piece.
4 is digitized and temporarily stored in an internal image memory (not shown). Camera 14
Is a line sensor in which pixels are arranged in the X direction.
When the Y table 13 moves in the Y direction in accordance with an instruction from the computer 17, two-dimensional image data is stored in the image memory. After the image capturing of the inspection area A is completed,
The XY table 13 moves so that the line sensor camera 14 is positioned on the inspection area B of the inspection target piece.

Next, the first image processing device 15 starts the primary inspection of the inspection area A. Host computer 17
Is a mark 4 indicating that the primary inspection is being performed at a position on the piece image 2 corresponding to the inspection area A on the inspection target piece.
Is displayed (FIG. 3C). The mark 4 is, for example, a green frame indicating the outer edge of the inspection area A. At the same time, the host computer 17 instructs the first image processing device 15 to capture an image of the inspection area B of the inspection target piece, and inputs an image to the position on the piece image 2 corresponding to the inspection area B on the inspection target piece. A mark 3 indicating that the vehicle is in the middle is displayed.

The image capture of the inspection area B by the XY table 13, the line sensor camera 14, and the first image processing device 15 is performed in the same manner as the area A. After the image capture of the area B is completed, the XY table 13 Moves so that the line sensor camera 14 is positioned on the inspection area C of the inspection target piece.

Here, the primary inspection method will be described. First, the first image processing device 15 performs positioning of the master pattern and the pattern to be measured such that the position of the positioning mark of the pattern to be measured stored in the image memory matches the position of the positioning mark of the master pattern. continue,
The first image processing device 15 binarizes the grayscale image of the measured pattern after the alignment. Then, the first image processing device 15 extracts edge data indicating the edge of the pattern to be measured from the binary image by performing a labeling process of giving the same label (name) to the connected pixels in the binary image.

Next, the first image processing device 15 compares the pattern to be measured thus extracted with the second and third master patterns to detect a defect candidate of the pattern to be measured.
FIG. 5 is a diagram for explaining this inspection method.

First, as shown in FIG. 5A, the pattern to be measured is compared with the second master pattern M1. When the logical product of the measured pattern P composed of a set of edge data n and the second master pattern M1 is calculated, the result of the logical product differs depending on whether the measured pattern P has a defect or a disconnection. For example, when each edge data has "1" as its value, and similarly, when the master pattern M1 has "1", if the measured pattern P has no loss or disconnection, the measured pattern P and the master pattern M1 Do not overlap, the result of the logical product is “0”.

On the other hand, if there is a defect in the pattern to be measured P as in the edge data n1 to n3, the pattern to be measured and the master pattern M1 overlap in this portion, and the result of the logical product is "1". . This is the same when the pattern to be measured has a disconnection. In this way, it is possible to detect loss or disconnection of the pattern to be measured. And
The image processing device 15 stores a position (the position of the edge data n2 in FIG. 5A) at which the result of the logical product is “1” and is recognized as a defect candidate.

Subsequently, as shown in FIG. 5B, the measured pattern is compared with the third master pattern M2. Similarly to the above, when the logical product of the measured patterns Pa and Pb and the third master pattern M2 is obtained, the result of the logical product differs depending on whether the measured patterns Pa and Pb have a protrusion or a short circuit. That is, when there is no protrusion or short circuit in the patterns Pa and Pb to be measured, the result of the logical product is “0”.

If the pattern Pa to be measured has a protrusion like the edge data n4 to n6, the pattern Pa to be measured overlaps the master pattern M2 at this portion, and the result of the logical product is "1". Similarly, edge data n7, n
When the patterns Pa and Pb to be measured are short-circuited as in 8, the result of the logical product is “1”. Thus, a protrusion or a short circuit of the pattern to be measured can be detected. Then, the image processing device 15 stores the position where the result of the logical product is “1” and is recognized as a defect candidate (in FIG. 5B, the positions of the edge data n5, n7, and n8).

The above-described primary inspection may be performed on the entire inspection area A. Next, the first image processing device 15
The position of the defect candidate in the inspection area A is transferred to the second image processing apparatus 16 as address information, and the primary inspection of the inspection area B is started. The second image processing device 16 has a first
Based on the address information sent from the image processing device 15 of the above, for the area of a predetermined size centered on the detected defect, the measured pattern is compared with the first master pattern to obtain an error. Perform the next inspection. This inspection method is the same as the above-described methods of FIGS.

The host computer 17 displays the mark 5 indicating that the secondary inspection is being performed at a position on the piece image 2 corresponding to the inspection area A (FIG. 3D). The mark 5 is, for example, a blue frame indicating the outer edge of the inspection area A. At the same time, the host computer 17 displays the mark 4 indicating that the primary inspection is being performed at a position on the piece image 2 corresponding to the inspection area B, and instructs the first image processing device 15 to capture the image of the inspection area C. Then, a mark 3 indicating that an image is being input is displayed at a position on the piece image 2 corresponding to the inspection area C.

The image capturing of the inspection area C by the XY table 13, the line sensor camera 14, and the first image processing device 15 is performed in the same manner as the area A. After the image capturing of the area C is completed, the XY table 13 Moves so that the line sensor camera 14 is positioned on the inspection area A of the next inspection target piece.

The second image processing device 16 that has completed the secondary inspection of the inspection area A transfers the inspection result to the host computer 17. When a defect is detected in the inspection area A, the host computer 17 receiving the inspection result displays, for example, a red NG mark 6 at a position on the piece image 2 corresponding to the position of the defect in the inspection area A. (Figure 3
(E)).

The first image processing device 15 that has completed the primary inspection of the inspection region B transfers the position of the defect candidate in the inspection region B to the second image processing device 16 as address information, Initiate the primary inspection. The second image processing device 16 performs a second inspection of the inspection area B based on the address information sent from the first image processing device 15.

The host computer 17 displays a mark 5 indicating that the secondary inspection is being performed at a position on the piece image 2 corresponding to the inspection area B, and displays the mark 5 on the piece image 2 corresponding to the inspection area C. Then, a mark 4 indicating that the primary inspection is being performed is displayed (FIG. 3E). The second image processing device 16 that has completed the secondary inspection of the inspection area B transfers the inspection result to the host computer 17, and the host computer 17 that has received the inspection result determines whether a defect is detected in the inspection area B. The NG mark 6 is displayed at a position on the piece image 2 corresponding to the position of the defect in the inspection area B (FIG. 3).
(F)).

After completing the primary inspection of the inspection area C, the first image processing apparatus 15 transfers the position of the defect candidate in the inspection area C to the second image processing apparatus 16 as address information, and
The image processing device 16 performs a secondary inspection of the inspection area C based on the address information. The host computer 17
At the position on the piece image 2 corresponding to the inspection area C, a mark 5 indicating that the secondary inspection is being performed is displayed (FIG. 3).
(F)).

The second image processing device 16 that has completed the secondary inspection of the inspection area C transfers the inspection result to the host computer 17 and receives the inspection result.
Indicates that when a defect is detected in the inspection area C, the inspection area C
NG at the position on the piece image 2 corresponding to the position of the defect in the
The mark 6 is displayed (FIG. 3 (g)). After the inspection of one piece 12 is completed in this way, image capturing of the inspection area A of the next inspection target piece is started in the same manner as described above.
Even if the inspection target piece moves to another piece 12, the inspection result of the previous inspection target piece (FIG. 3 (g)) remains displayed.

In this embodiment, the inspection piece is singular. However, as shown in FIG. 1, a plurality of cameras 14 are provided, and the first and second image processing devices 15 and 16 are prepared by the number of cameras 14. Then, a plurality of inspection target pieces can be inspected simultaneously. Further, in the present embodiment, a pattern inspection apparatus using a green sheet as an inspection work has been described as an example. However, the present invention is not limited to this, and it goes without saying that the present invention may be applied to other inspection apparatuses.

[0039]

According to the present invention, a work image similar to the inspection work is displayed, and the inspection status of the inspection area is displayed at a position on the work image corresponding to the inspection area. Since the mark is displayed, it is possible to easily confirm in real time the inspection status such as the position of the inspection area where the inspection is currently performed, the type of the inspection being performed, or the inspection result up to the present.

[Brief description of the drawings]

FIG. 1 is a block diagram of a pattern inspection apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of creating second and third master patterns.

FIG. 3 is a diagram showing a state of an inspection status display screen of the display device.

FIG. 4 is a diagram for explaining a flow of processing in the pattern inspection apparatus.

FIG. 5 is a diagram for explaining an inspection method based on comparison with second and third master patterns.

FIG. 6 is a diagram for explaining a conventional inspection method for detecting disconnection.

FIG. 7 is a diagram for explaining a conventional inspection method for detecting disconnection.

FIG. 8 is a diagram for explaining a conventional inspection method for detecting a short circuit.

FIG. 9 is a diagram for explaining a conventional inspection method for detecting a defect or a protrusion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Work image, 2 ... Piece image, 3,4,5 ... Mark, 6 ... NG mark, 11 ... Green sheet, 12 ... Piece, 13 ... XY table, 14 ... Line sensor camera, 15 ... First Image processing device, 16: second image processing device, 17: host computer, 18: display device.

Claims (3)

[Claims] 1. An inspection apparatus for automatically inspecting an inspection work by capturing an image of the inspection work with a camera, wherein the inspection work is a method of displaying an inspection state of the inspection work, and corresponds to the inspection work on a screen of the display device. Displaying a work image, and displaying a mark representing an inspection state of the inspection area at a position on the work image corresponding to an inspection area as an inspection execution unit on the inspection work. . 2. The inspection status display method according to claim 1, wherein a frame-like mark indicating an outer edge of the inspection area is displayed as the mark indicating the inspection status, and a line type is changed for each inspection status. An inspection status display method characterized by the following. 3. The inspection status display method according to claim 1, wherein a frame-like mark indicating an outer edge of the inspection area is displayed as the mark indicating the inspection status, and is displayed in different colors for each inspection status. Inspection status display method.