Browsing by Author "Lin, Sheng-Feng"

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Near-infrared imaging system for nondestructive inspection of micro-crack in wafer through dicing tape
(2015-10-01)
Lin, Sheng-Feng
;
Chen, Cheng-Huan
;
Lo, Cheng-Yao
;
光電工程學系
;
顯示科技研究所
Detection of wafer/die crack after the wafer dicing process is important for yield rate control prior to packaging. The traditional approach of microscopic examination is done after the dies are stripped from the dicing tape, and further crack propagation could result from this pick-and-place process. An on-tape crack inspection technique is proposed in this paper so that the crack from the dicing process can be clearly identified. The issues of seeing through the silicon substrate and the scattering at the dicing tape have been resolved, respectively, using a near-infrared wavelength of 1100 nm for illumination and using a feeding index matching liquid for filling the rough surface of the tape. Both the illumination and imaging optics of the inspection system have been designed and simulated with a ray-tracing program, and the prototype demonstrates the ability of seeing through the silicon substrate and dicing tape as well as detecting micro-crack down to 1.25 mu m, whose resolution is sufficient for most applications of die crack inspection. (C) 2015 Optical Society of America
Nondestructive Optical Inspection System for the Dicing Street Quality of Copper/Low-k Wafer
(2015)
Lin, Sheng-Feng
;
Chen, Cheng-Huan
;
Lo, Cheng-Yao
;
光電工程學系
;
顯示科技研究所
To resolve the issue in detecting sidewall crack defect mode in the die singulation of copper/low-k wafer after laser pre-groove/cleaning process, we combine a dedicated optical system with automatic optical inspection system in the production line for the nondestructive wafer-by-wafer optical inspection system to inspect the dicing street quality of copper/low-k wafer. Experiment shows that the sidewall crack defect can be clearly identified with the proposed inspection system and it is potentially applicable for the production line.
Optical Design of Compact Space Autonomous Docking Instrument with CMOS Image Sensor and All Radiation Resistant Lens Elements
(2020-08-01)
Lin, Sheng-Feng
;
Chen, Cheng-Huan
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交大名義發表
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National Chiao Tung University
Built-in autonomous stereo vision devices play a critical role in the autonomous docking instruments of space vehicles. Traditional stereo cameras for space autonomous docking use charge-coupled device (CCD) image sensors, and it is difficult for the overall size to be reduced due to the size of the CCD. In addition, only the few outermost elements of the camera lens use radiation-resistant optical glass material. In this paper, a complementary metal-oxide semiconductor (CMOS) device is used as the image sensor, and radiation-resistant optical glass material is introduced to all lens elements in order to make a compact and highly reliable space grade instrument. Despite the limited available material, a fixed focus module with 7 lens elements and overall length of 42 mm has been achieved, while meeting all the required performance demands for the final vision-guided docking process.
Optimal F-Number of Ritchey-Chretien Telescope Based on Tolerance Analysis of Mirror Components
(2020-08-01)
Lin, Sheng-Feng
;
Chen, Cheng-Huan
;
Huang, Yi-Kai
;
交大名義發表
;
National Chiao Tung University
The Ritchey-Chretien telescope has been the key optical module for remote sensing instruments (RSI), in which the root mean square (RMS) random surface wavefront error and the alignment error of the primary and the secondary mirror takes the highest weighting in the tolerance analysis for the fabrication and assembly of the telescope. Therefore, the higher tolerance of those items becomes preferable for higher efficiency of RSI manufacturing. In this paper, the correlation between those tolerance items and the f-number of the telescope has been investigated. Although the f-number is normally a system parameter well specified in the beginning of the design process, it is not very rigid in practice and has a certain amount of allowable range. The optimal f-number can then be chosen based on the consideration of those key tolerance items. The proposed concept can be generalized as a novel methodology of design for tolerance.