JPH102866A - Pattern inspecting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out correction and transfer of a mask pattern within a short time. SOLUTION: Recognition devices 7a-7d compared an objective pattern to be measured photographed by a camera 4 with a master pattern, which is a reference, to determine the quality of the objective pattern to be measured. At the time of correcting the master pattern, the recognition devices 7a-7d transfer the corrected data of divided regions to a memory apparatus 9 of a host CPU 8. At the time of starting inspection, the CPU 8 compares the master pattern whose form number is stored in the memory apparatus 9 with the master pattern stored in the recognition devices 7a-7d. In the case divided regions with old form number exist in the master pattern of the recognition devices 7a-7d, the corrected data with the new form number is transferred to the recognition devices 7a-7d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a pattern inspection apparatus for inspecting a pattern formed on a green sheet or a film carrier.

[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.

[0003] As another mounting technique, TAB is used.
(Tape Automated Bonding) is known. TAB method is a polyimide film carrier (TAB tape)
The copper foil pattern formed thereon is joined to the electrode of the IC chip to form an external lead. The copper foil pattern is formed by attaching a copper foil to a film with an adhesive and etching this.

In such a green sheet or film carrier, a pattern is visually inspected by a human using a microscope after the pattern is formed. However, visually inspecting a fine pattern requires skill and has a problem of overworking the eyes. Therefore, as an alternative to the visual inspection, there has been proposed a pattern inspection apparatus for automatically inspecting a pattern formed on a film carrier or the like by taking an image with a TV camera (for example, Japanese Unexamined Patent Application Publication No.
-341960).

FIG. 1 is a block diagram of a pattern inspection apparatus according to a first embodiment of the present invention. The configuration of the conventional pattern inspection apparatus is almost the same as that of the conventional pattern inspection apparatus. . In this pattern inspection apparatus, a pattern that has been previously determined to be non-defective is captured by the camera 4, and the captured grayscale image is digitized by the A / D converter 5. Then, by storing the corrected image data in the storage device 9 of the host CPU 8, a master pattern serving as a reference for comparison with the pattern to be measured is created.

However, when the master pattern is created from non-defective products of the pattern to be measured, a non-defective sample must be prepared, but it is impossible to represent all the measured patterns with the selected non-defective sample. In other words, the conforming sample does not always conform to the center of the standard even though it is within the standard. In addition, since the real object is imaged by the camera, the camera, lighting, or other image input conditions (for example, dust attached to the camera or pattern) are added to the master pattern. As described above, when creating a master pattern from the actual thing, the captured pattern is partially corrected to create a final master pattern. In this case, after the pattern to be measured is determined to be defective, it is often noticed that there is a defect in the master pattern. Therefore, when a new master pattern is created, the master pattern is often revised.

When a master pattern is corrected, the conventional pattern inspection apparatus can correct the master pattern only by one of the recognition devices 7a to 7d for judging the quality of the pattern. The corrected recognition device stores the entire master pattern area (that is, if the inspection target is a green sheet, in the storage device 9 controlled by the host CPU 8)
Transfer the data for one green sheet). Thereby, the data in the storage device 9 is updated. When the inspection is started again, the host CP is sent to the recognition devices 7a to 7d connected to the CPU 8 by the digital interface.
Transfer the data of the entire area of the master pattern from U8,
The data of the recognition devices 7a to 7d has been updated.

[0008]

As described above, in the conventional pattern inspection apparatus, when it is necessary to correct the master pattern, the entire area of the master pattern is transferred from the recognition device that has performed the pattern correction to the storage device of the host CPU. Transfer,
Since the entire area of the master pattern is transferred from the storage device to the recognizing device at the start of the test, there is a problem that it takes a long time until the next test starts. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a pattern inspection apparatus that can correct and transfer a master pattern in a short time.

[0009]

According to a first aspect of the present invention, there is provided a camera for capturing an image of a pattern to be measured, and a master pattern serving as a reference and a captured master pattern. A plurality of recognition devices that determine the acceptability of the pattern to be measured by comparing each divided region into sizes, a storage device that stores data of the master pattern, and a master pattern stored in the storage device at the start of inspection And a host CPU for transferring the data of the divided region to the recognition device. The recognition device can correct the master pattern for each divided region, and transfers the data of the corrected divided region to the storage device. The master pattern stored in the storage device and the master pattern stored in the recognizing device are provided with the version number of the master pattern that is assigned to each divided area and revised each time a correction is made. Compared in over emissions, when the edition number exists old divided area in the master pattern recognition device,
The data of the corresponding divided area is transferred to the recognition device, and when the version numbers match, the data is not transferred. As described above, the recognition device stores the data of the corrected divided area in the host C
Transferred to the storage device of the PU, and when the inspection starts, the host CPU
When there is a divided area with an old version number in the master pattern of the recognition device, the data of the corrected new version number is transferred to the recognition device, and the version number of the master pattern of the storage device matches the master pattern of the recognition device. Do not transfer data. According to a second aspect of the present invention, the master pattern can be corrected in each of the plurality of recognition devices.

[0010]

Next, a pattern inspection apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a flowchart for explaining the operation of the pattern inspection apparatus of FIG. The pattern 2 is formed on the green sheet 1 by screen printing.

Before inspecting such a green sheet, a green sheet 1 which has been previously determined to be a non-defective product is subjected to X-ray printing.
It is placed on the Y table 3 and imaged by the line sensor camera 4 to create a master pattern (step 101 in FIG. 2). At this time, the size of the image captured by the line sensor camera 4 is, for example, 4096 in the X direction.
Pixel. Then, under the control of the host CPU 8, X
When the camera 4 captures an image while moving the Y table 3 in the Y direction, the size of the image in the Y direction becomes, for example, 8192 pixels.

A grayscale image of 4096 horizontal pixels × 8192 vertical pixels captured by the camera 4 is digitized by the A / D converter 5 and stored in the image memory 6. The image memory 6 divides the stored image data into divided areas each having a size of 512 pixels horizontally by 480 pixels vertically, and transfers the image data to the recognition devices 7a to 7d for each of the divided areas. Then, the image data is transferred to and stored in the storage device 9 controlled by the host CPU 8 after necessary corrections are made in the recognition devices 7a to 7c. In this manner, the entire area of the master pattern is stored in the storage device 9, and the creation of the master pattern ends.

Next, the inspection of the pattern to be measured will be described.
First, the operator operates the keyboard 10 to input a unique product name for the green sheet to be inspected (step 102). The host CPU 8 reads the corresponding master pattern from the storage device 9 based on the input product type name, and determines whether the storage device (not shown) in the recognition devices 7a to 7d stores the master pattern of the same product type. (Step 103).

In this case, since the inspection of a green sheet in which a new master pattern is registered is performed, the recognition device 7a to 7d has not yet stored the master pattern. Then, the host CPU 8 transfers the data of the entire area of the master pattern read from the storage device 9 to the recognition devices 7a to 7d (step 104). Thus, the recognition devices 7a-
The master pattern is stored in the storage device in 7d.

Next, the green sheet 1 to be inspected is
Is placed on the XY table 3, which is imaged by the line sensor camera 4 to capture the pattern to be measured (step 105). The way of imaging is exactly the same as that of the master pattern. Horizontal 4096 imaged by camera 4
The gray scale image of 8192 pixels × 8192 pixels is digitized by the A / D converter 5 and stored in the image memory 6.
The image memory 6 stores the stored image data in 512 horizontal pixels.
The image data is divided into divided areas each having a size of 480 pixels vertically, and image data is transferred to the recognition devices 7a to 7d for each divided area.

The recognizing devices 7a to 7d simultaneously check the image data of the four divided areas transmitted in parallel from the image memory 6 (step 106). Each of the transferred divided areas is compared with the corresponding divided area of the registered master pattern, thereby checking whether the pattern is thick, thin, broken, short-circuited, or the like. Then, the inspection result is sent to the host CPU 8. By repeating such inspection for each of the four divided regions, the pattern inspection of all divided regions is completed.

If there is no problem in the pattern inspection by the recognition devices 7a to 7d and it is determined that the pattern is non-defective, step 10
Returning to step 3, the inspection of the next green sheet can be started. At this time, since the master patterns have already been stored in the recognition devices 7a to 7d and there is no correction of the master pattern described later, there is no transfer of the master pattern from the host CPU 8 to the recognition devices 7a to 7d.
You can proceed to

On the other hand, in step 106, the recognition device 7
When a to 7d detect a pattern defect, the operator determines whether or not this result is due to a defect in the master pattern (step 107). If there is no problem with the master pattern, the inspected green sheet is defective (step 108).

If the operator determines that the master pattern has a defect (for example, the pattern width is wider than the standard) and the master pattern needs to be corrected, the operator operates the keyboard 10. To indicate necessary corrections. In response to this instruction, the recognition device 7a, 7b, 7c or 7d that has detected the pattern defect corrects the designated portion of the corresponding divided area of the master pattern (step 10).
9). A version number (version number) is assigned to the master pattern for each divided area. Each time a correction is made, this version number is revised and increased by one (that is, upgraded).

Then, the recognizing devices 7a, 7 which have been corrected
b, 7c or 7d transfers only the data of the corrected divided area to the storage device 9 of the host CPU 8 (step 11).
0). Thereby, the host CPU 8 replaces the data of the corresponding divided area of the master pattern stored in the storage device 9 with the received divided area. Thus, the data of the divided area to be corrected is replaced with the corrected new data, and the work of correcting the master pattern ends.

At the start of the inspection of the next green sheet, the host CPU 8 determines whether a master pattern of the same type is stored in the storage device in the recognition devices 7a to 7d in the same manner as described above (step 103). Here, the corresponding master pattern is already stored in the recognition devices 7a to 7d. Then, the host CPU 8 recognizes the version number of the master pattern stored in the storage device 9 by the recognition devices 7a to 7d.
Is compared with the version number of the master pattern stored for each divided area (step 111).

If the version numbers of the divided areas match, the flow directly proceeds to step 105 to start inspection. On the other hand, when the master pattern is partially corrected as described above, the host CPU 8 determines that the divided pattern having the version number older than the master pattern of the storage device 9 exists in the master patterns of the recognition devices 7a to 7d. Only the data of the divided areas whose numbers do not match are transferred to the recognition devices 7a to 7d (step 112).

As a result, the recognition devices 7a to 7d replace the data of the divided area corresponding to the stored master pattern with the received divided area. In this way, the data of the divided area having the old version number is replaced with the new data.
Note that the recognition device 7a that has performed the correction of the master pattern,
Since 7b, 7c or 7d already has the upgraded master pattern, there is no need to send data to this recognition device.

In the present embodiment, the pattern 2 printed on the green sheet 1 has been described as an example.
It is needless to say that the present invention is not limited to this, and may be a pattern formed on another substrate such as a film carrier.

[0025]

According to the present invention, the recognition device transfers the data of the divided area of the corrected master pattern to the storage device of the host CPU, and at the start of the inspection, the host CPU changes the version number to the master pattern of the recognition device. By transferring data of a new version number to the recognition device when an old divided region exists, only the data of the corrected divided region is transferred between the recognition device and the storage device of the host CPU. Thus, the entire area of the master pattern is not transferred. As a result, in the case where the size of the conventional master pattern becomes enormous, the transfer of the master pattern takes, for example, about 20 minutes. However, the present invention requires only about 2 to 3 minutes. The time from the correction to the start of the next inspection can be greatly reduced.

In addition, since the master pattern can be corrected in each of the plurality of recognition devices, when the pattern to be measured under inspection becomes defective, the recognition device that has detected the defect detects the master pattern. Therefore, the master pattern can be easily corrected in a shorter time.

[Brief description of the drawings]

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

FIG. 2 is a flowchart for explaining the operation of the pattern inspection apparatus of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Green sheet, 2 ... Pattern, 3 ... XY table, 4 ... Line sensor camera, 5 ... A / D converter, 6 ...
Image memory, 7a to 7d: recognition device, 8: host CP
U, 9 ... storage device, 10 ... keyboard.

Claims (2)

[Claims] 1. A camera for imaging a pattern to be measured, and comparing the captured pattern to be measured and a reference master pattern for each divided area obtained by dividing these patterns into a predetermined size. A pattern inspection apparatus comprising: a plurality of recognition devices for judging pass / fail; a storage device for storing master pattern data; and a host CPU for transferring the master pattern data stored in the storage device to the recognition device at the start of inspection. The recognition device is capable of correcting a master pattern for each divided region and transferring data of the corrected divided region to the storage device. The host CPU is provided with a correction for each divided region. The version number of the master pattern that is revised each time it is applied to the master pattern stored in the storage device and the master pattern stored in the recognition device When the master pattern of the recognition device includes a divided region having an old version number, the data of the corresponding divided region is transferred to the recognition device, and when the version numbers match, the data is not transferred. Characteristic pattern inspection equipment. 2. The pattern inspection apparatus according to claim 1, wherein the plurality of recognition devices are each capable of correcting a master pattern.