Flaw inspection device and flaw inspection method

Patent metadata

Field	Value
Publication number	US-10466181-B2
Application number	US-201616085890-A
Country	US
Kind code	B2
Filing date	Mar 30, 2016
Priority date	Mar 30, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

The present invention aims at providing a defect inspection technique capable of setting parameters used for detecting a defect with a less burden to a user. A defect inspection device according to the present invention receives multiple reference values input by the user and calculates a defect extraction condition so as to optimize an evaluation value calculated with the use of the reference values, the number of actual reports, and the number of false reports (refer to FIG. 8).

First claim

The invention claimed is:

1. A defect inspection device for inspecting a defect of an inspection target, comprising:
an image generator that generates an exterior image of the inspection target;
a feature amount calculator that calculates a feature amount of the exterior image;
a storage device that stores extraction condition data describing an initial value of a condition for extracting the defect of the inspection target;
a defect determination processor that compares the feature amount with the condition to extract the defect of the inspection target;
a display that outputs information representing the defect extracted by the defect determination processor; and
an interface that receives a designation input for designating whether the defect extracted by the defect determination processor is an actual report or a false report,
wherein the defect determination processor receives a plurality of reference values through the interface and calculates the condition under which an evaluation value calculated using the number of actual reports, the number of false reports, and the reference values becomes optimum for each of the reference values,
the defect determination processor extracts the defect of the inspection target by using the condition calculated for each of the reference values, and
the display outputs the condition calculated by the defect determination processor for each of the reference values for each of the reference values and outputs the defects extracted using the conditions calculated for each of the reference values and outputs information representing the extracted defect by using the condition calculated by the defect determination processor for each of the reference values.

2. The defect inspection device according to claim 1 ,
wherein the defect determination processor calculates an actual report rate representing a rate of the number of actual reports to a total of the number of actual records and the number of false reports and calculates the evaluation value by using the actual report rate to extract the defect by using the actual report rate as the condition.

3. The defect inspection device according to claim 2 ,
wherein the defect determination processor receives, as each of the reference values, a numerical value designating a weight of the actual report rate at the evaluation value, and calculates the evaluation value using the weight.

4. The defect inspection device according to claim 1 ,
wherein the defect determination processor classifies the defect of the inspection target according to the feature amount and sets a weight coefficient for each classification of the defect, and
the defect determination processor sets the weighting coefficient to increase the evaluation value more as the weight coefficient is larger for the classification belonging to the actual report, and decrease the evaluation value more as the weight coefficient is larger for the classification belonging to the false report.

5. The defect inspection device according to claim 1 ,
wherein the defect determination processor receives a numerical value of a defect capture rate indicating a rate of the number of actual reports to the number of actual reports detected by using the initial value of the condition as the reference value, and
the defect determination processor calculates the evaluation value by using the defect capture rate to extract the defect by using the defect capture rate as the condition.

6. The defect inspection device according to claim 1 ,
wherein the defect determination processor receives a numerical value of a false report rate representing a rate of the number of false reports to a total of the number of actual reports and the number of false reports as the reference value, and
the defect determination processor calculates the evaluation value by using the false report rate to extract the defect by using the false report rate as the condition.

7. The defect inspection device according to claim 1 ,
wherein the defect determination processor receives a numerical value of a defect residual rate representing a rate of the number of false reports to the number of false reports detected by using the initial value of the condition as the reference value, and
the defect determination processor calculates the evaluation value by using the defect residual rate to extract the defect by using the defect residual rate as the condition.

8. The defect inspection device according to claim 1 , further comprising:
a plurality of detection systems that acquire a pixel value of the exterior image by imaging the inspection target and deliver the pixel value to the image generator; and
a difference calculator that calculates a difference between the pixel value of the exterior image acquired by each of the detection systems and a pixel value of a reference image for each of the detection systems,
wherein the defect determination processor obtains a linear sum of the differences respectively calculated by the difference calculator for one or more of the detection systems, and determines that a pixel corresponding to the difference is defective when the linear sum exceeds a first determination threshold.

9. The defect inspection device according to claim 8 ,
wherein the defect determination processor sets a second determination threshold that is the same as or different from each other for each of the detection systems in advance, and
the defect determination processor determines that the pixel corresponding to the difference is defective when the linear sum exceeds the first determination threshold and the difference exceeds the second determination threshold for all of the detection systems.

10. The defect inspection device according to claim 1 , further comprising:
a plurality of detection systems that acquire a pixel value of the exterior image by imaging the inspection target and deliver the pixel value to the image generator, and
a difference calculator that calculates a difference between the pixel value of the exterior image acquired by each of the detection systems and a pixel value of a reference image for each of the detection systems,
wherein the defect determination processor sets a second determination threshold that is the same as or different from each other for each of the detection systems in advance, and determines that a pixel corresponding to the difference is defective when the difference exceeds the second determination threshold for all of the detection systems.

11. The defect inspection device according to claim 1 ,
wherein the image generator generates the exterior image in each of partial areas of the inspection target and assigns an identifier of each of the partial areas to the exterior image, and
the defect determination processor extracts the defect of the inspection target for each of the partial areas.

12. The defect inspection device according to claim 1 ,
wherein the image generator generates the exterior image in each of partial areas of the inspection target and assigns an identifier of each of the partial areas to the exterior image, and
the defect determination processor collectively extracts the defects of the inspection target for all of the partial areas and calculates the evaluation value by using the number of actual reports and the number of false reports for all of the partial areas to optimize the evaluation value for a total of all of the partial areas.

13. The defect inspection device according to claim 1 , further comprising:
a reference image combiner that generates a reference image by combining a plurality of the exterior images of the inspection target together;

Assignees

• Hitachi High Tech Corp

Inventors

• Honda Toshifumi
• Urano Takahiro
• Kobayashi Mamoru
• Hatano Hisashi
• Sakurai Hironori

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P74/20

  characterised by the properties tested or measured, e.g. structural or electrical properties · CPC title

• G01N21/956 Primary

  Inspecting patterns on the surface of objects {(contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20)} · CPC title

• G05B19/41875 Primary

  characterised by quality surveillance of production · CPC title

• G01N21/8851 Primary

  Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges (G01N21/8806 and G01N21/93 - G01N21/95692 take precedence; optical measurement of dimensions G01B11/00; optical scanning G02B26/10; image transformation G06T3/00; computerised image enhancement G06T5/00; image processing per se for flaw detection G06T7/0002) · CPC title