By SEC Co.,Ltd
Tomosynthesis is a method reconstructing 3D image only using projection image of limited angle unlike CT. It has studied from 1930’s, but Digital Detector did not existed at that time and after CT reconstructing method was developed in 1972, people’s interest has diminished. However, it has emerged again as important study subject by development of Fast Digital FPD and computer technology. Scanning Geometry for Laminography is very various and 6 types of it can be seen in Figure 5. Tomosynthesis can scan in short time by using projection image of limited angle unlike CT and can efficiently scan thin and large product which is hard to scan with CT. Though, gaining 3D image as same quality as CT is very difficult due to using data of limited angle. Area able to accurately reconstruct in Tomosynthesis can be seen in Figure 6. Similar image quality with CT can be gained in the area of A 1~B 1, A 2~B 2, A 3~B 3, A 4~B 4 in 5.(b), but the image quality of other area is not as good as CT. However, if product is thin and wide, the disadvantage can efficiently be overcome. Figure 7 is the result of reconstructing projection image of semiconductor data gained only by limited angle of 60° using our repetitive Tomosynthesis reconstruction algorithm.
