Defect inspection method

1. A defect inspection method comprising:

exposing a target object to a tracer having higher absorptance for a neutron ray than the target object;

radiating the neutron ray to the target object exposed to the tracer;

generating at least one neutron image based on the neutron ray having penetrated the target object exposed to the tracer; and

detecting a defect of the target object based on the generated at least one neutron image.

2. The defect inspection method of claim 1 ,

wherein the detecting the defect comprises judging that the defect occurs at a position when detecting the position where the tracer permeates in the target object based on the generated at least one neutron image.

3. The defect inspection method of claim 1 ,

wherein, in the exposing, water is used as the tracer.

4. The defect inspection method of claim 1 ,

wherein, in the detecting, a crack in a soldered portion is detected as the defect.

5. The defect inspection method of claim 1 , further comprising

drying the tracer after exposing the target object thereto,

wherein the at least one neutron image comprises a plurality of neutron images;

wherein, in the radiating, the neutron ray is radiated to the target object during a period of drying the tracer;

wherein, in the generating, the plurality of neutron images are generated until the tracer is dried; and

wherein, in the detecting, the defect of the target object is detected based on the generated plurality of neutron images.

6. The defect inspection method of claim 5 ,

wherein the exposing comprising:

housing the target object in a hermetic space; and

evaporating the tracer to supply to the hermetic space, and

wherein the drying comprising:

supplying dry gas into the hermetic space; and

discharging the gas in the hermetic space.

7. The defect inspection method of claim 1 ,

wherein the exposing comprising:

housing the target object in a hermetic space; and

evaporating the tracer to supply to the hermetic space.