Defect inspection apparatus and defect inspection method

Patent metadata

Field	Value
Publication number	US-2022026396-A1
Application number	US-201817413374-A
Country	US
Kind code	A1
Filing date	Dec 20, 2018
Priority date	Dec 20, 2018
Publication date	Jan 27, 2022
Grant date	—

Abstract

A defect inspection apparatus (100) is provided with and an excitation unit (1) for exciting elastic waves, an irradiation unit (2) for emitting laser light, a measurement unit (3) for measuring interference light, and a control unit (4). The control unit is configured to acquire an image (61) representing a vibration state of an inspection target object (7) in a measurement area based on a measurement result of the measurement unit (3), detect a discontinuous portion in a vibration state in the measurement area from the image representing the vibration state as a defect (73), and identify a type of the defect based on at least one of a shape (62) of the detected defect and the vibration state of a defective portion.

First claim

1 . A defect inspection apparatus comprising:
an excitation unit configured to excite elastic waves in an inspection target object; an irradiation unit configured to emit laser light to a measurement area of the inspection target object in a state in which the elastic waves are excited by the excitation unit; a measurement unit configured to cause the laser light reflected at mutually different positions in the measurement area to interfere with each other to acquire interference light and measure the interference light; and a control unit, the control unit being configured to acquire an image representing a vibration state of the inspection target object in the measurement area based on a measurement result of the measurement unit, detect a discontinuous portion in the vibration state in the measurement area from the image representing the vibration state as a defect, and identify a type of the defect based on at least one of a shape of the detected defect and the vibration state of a defective portion wherein the image representing the vibration state is a moving image in which a temporal change of a vibration displacement is displayed.

2 . The defect inspection apparatus as recited in claim 1 ,
wherein the control unit is configured to extract an area where the vibration state is discontinuous from the image representing the vibration state as a shape of the defect, identify a type of the defect as a crack in a case where the shape of the defect is linear, and identify a type of the defect as a delamination in a case where the shape of the defect is planar.

3 . The defect inspection apparatus recited in claim 2 ,
wherein the control unit identifies the type of the defect based on an area and a perimeter of the shape of the extracted defect.

4 . The defect inspection apparatus as recited in claim 3 ,
wherein the control unit identifies the type of the defect based on a ratio of the area of the shape of the extracted defect to the perimeter of the shape of the extracted defect.

5 . The defect inspection apparatus as recited in claim 1 , further comprising:
a display unit configured to display a defect type indication indicating the type of the defect identified by the control unit, wherein the display unit displays at least one of an image representing the shape of the defect and an image indicating the vibration state together with the defect type indication.

6 . (canceled)

7 . A defect inspection method comprising:
exciting elastic waves in an inspection target object; emitting laser light to a measurement area of the inspection target object in a state in which the elastic waves are excited; causing the laser light reflected at mutually different positions in the measurement area to interfere with each other to acquire interference light and measuring the interference light; acquiring a moving image in which a temporal change of a vibration displacement is displayed as an image representing a vibration state of the inspection target object in the measurement area based on a measurement result; detecting a discontinuous portion in the vibration state in the measurement area from the moving image in which the temporal change of the vibration displacement is displayed as a defect; and identifying a type of the defect based on at least one of a shape of the detected defect and the vibration state of a defective portion.

Assignees

• Shimadzu Corp

Inventors

• Hatahori Takahide
• Takubo Kenji
• Yoshida Koki

Classifications

• G01N2291/0289

  Internal structure, e.g. defects, grain size, texture · CPC title

• G01N29/2418 Primary

  using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics (photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046) · CPC title

• G01N29/0609

  Display arrangements, e.g. colour displays (indicating or recording in connection with measuring in general G01D) · CPC title

• G01N29/043

  in the interior, e.g. by shear waves · CPC title

• G01N29/069

  Defect imaging, localisation and sizing using, e.g. time of flight diffraction [TOFD], synthetic aperture focusing technique [SAFT], Amplituden-Laufzeit-Ortskurven [ALOK] technique · CPC title