Browsing by Author "Lin, Jim-Wein"

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Highly efficient femtosecond pulse stretching by tailoring cavity dispersion in erbium fiber lasers with an intracavity short-pass edge filter
(2011-08-15)
Chen, Nan-Kuang
;
Liu, Feng-Zhou
;
Chuang, Hsiu-Po
;
Lai, Yinchieh
;
Yang, Shang-Da
We demonstrate highly efficient pulse stretching in Er(3+)-doped femtosecond mode-locked fiber lasers by tailoring cavity dispersion using an intracavity short-pass edge filter. The cavity dispersion is preset at around zero to obtain the shortest pulsewidth. When the cutoff wavelength of the short-pass edge filter is thermo-optically tuned to overlap the constituting spectral components of mode-locked pulses, large negative waveguide dispersion is introduced by the steep cutoff slope and the total cavity dispersion is moved to normal dispersion regime to broaden the pulsewidth. The time-bandwidth product of the mode-locked pulse increases with the decreasing temperature at the optical liquid surrounding the short-pass edge filter. Pulse stretch ratio of 3.53 (623.8fs/176.8fs) can be efficiently achieved under a temperature variation of 4 degrees C. (C) 2011 Optical Society of America
Optimization of laser release process for throughput enhancement of fan-out wafer-level packaging
(2018-01-01)
Lee, Chia-Hsin
;
Su, Jay
;
Liu, Xiao
;
Wu, Qi
;
Lin, Jim-Wein
Fan-out wafer-level-packaging (FOWLP) technology has been developed with various advantages, such as smaller form factor, lower cost, and simplified supply chain for heterogeneous integration. There have been several process schemes like chip-first or chip-last FOWLP integration discussed widely in conferences in recent years. One process in all of these process schemes has in common is the use of a temporary carrier for subsequent redistribution layer (RDL) formation, chip stacking and molding processes. Although the separation of a temporary carrier from the reconstituted wafer could be achieved without significant hurdles, there were few studies addressing optimization of carrier separation for throughput enhancement. Thus, this paper is designed to address the needs in optimizing carrier separation process based upon laser ablation technology. Two phases of experiments were designed to select the appropriate laser release layer and define optimal laser settings. The first experiment was used to evaluate correlation of the laser absorption, laser energy, and spot pitch versus completeness of laser ablation. The second experiment included RDL-first FOWLP integration. At first, 300-mm glass carriers (1000 mu m thick) with coefficient of thermal expansion of 8 ppm/degrees C were treated by selected laser release layers. After deposition of 0.05-mu m Ti/0.15 mu m Cu on the glass carrier, passivation of around 8 mu m was coated and patterned by lithography for electroplating Cu interconnections with a density of approximately 10% of the surface area. Subsequently, die bonding, build-up layers, or molding compound were applied on top to form a 200-mu m reconstituted wafer. The reconstituted wafer was then separated from the glass carrier through a laser ablation process using a 355-nm laser to determine optimal throughput. Experiments to study correlation of laser release layer with laser settings along with a demonstration of full RDL-first FOWLP integration are discussed thoroughly to address the need of throughput enhancement, which could serve as cornerstone for realizing cost-effective RDL-first FOWLP.
Study on Low Temperature Cu Bonding and Temporary Bond/De-Bond for RDL-First Fan-Out Panel Level Package
(2017-01-01)
Ko, Cheng-Ta
;
Yang, Kai-Ming
;
Lin, Jim-Wein
;
Wang, Chih-Lun
;
Chou, Tzu-Chieh
In this study, Cu-Cu bonding with pillar-concave structure on a polymer layer was investigated to realize better bonding quality at lower temperature, while a low-stress release layer for temporary bond and de-bond by laser ablation was demonstrated to handle a glass panel for re-distribution layer (RDL) process. The low temperature technology can be potentially applied for RDL-first fan-out panel level package (FOPLP).