Author Affiliations
1College of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen Key Lab of Urban & Civil Engineering Disaster Prevention & Reduction, Shenzhen, Guangdong 518055, China;2Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34708, Republic of Koreashow less
Fig. 1. Overall structure diagram of linear laser phase-locked thermal imaging system for semiconductor chip detection consisting of excitation, sensing, and control units
Fig. 2. Overview of baseline-free crack visualization algorithm
Fig. 3. Diagrams of thermal wave generation by modulated CW laser beam and corresponding thermal response captured by IR camera. (a) Intensity of modulated CW excitation laser; (b) corresponding thermal response in time domain
Fig. 4. Roberts cross convolution kernels. (a) Compute Kx of gradient edge at +45°; (b) compute Ky of gradient edge at -45°
Fig. 5. Experimental setup of linear laser phase-locked thermal imaging technology for detecting crack of semiconductor chip
Fig. 6. Semiconductor pressed chip specimens
Fig. 7. Microscopic images of semiconductor chip specimens with cracks. (a) Vertical cracks of pressed chip; (b) horizontal cracks of pressed chip
Fig. 8. Typical raw thermal images obtained from pressed chips. (a) Vertical line excitation on intact chip; (b) horizontal line excitation on intact chip; (c) vertical line excitation on vertically cracked chip; (d) horizontal line excitation on horizontally cracked chip
Fig. 9. Raw thermal images obtained from intact chip with vertical line excitation. (a) 0 ms; (b) t (50 ms); (c) T (500 ms)
Fig. 10. Phase-locked amplitude images obtained from raw thermal images in Fig. 8. (a) Vertical line excitation on intact chip; (b) horizontal line excitation on intact chip; (c) vertical line excitation on vertically cracked chip; (d) horizontal line excitation on horizontally cracked chip
Fig. 11. Discontinuous images obtained from chips. (a) Without crack; (b) with vertical crack; (c) with horizontal crack
Fig. 12. Final images obtained after de-noising process. (a) Without crack; (b) with vertical crack; (c) with horizontal crack