Browsing by Author "Chiang, Tzu Hsuan"

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A study of encapsulation resin containing hexagonal boron nitride (hBN) as inorganic filler
(2006-06-01)
Chiang, Tzu Hsuan
;
Hsieh, T. -E.
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Preparation and property characterization of encapsulation resin contained hexagonal boron nitride (hBN) as inorganic filler were carried out in this work. The dielectric properties, coefficient of thermal expansion (CTE), thermal conductivity, curing kinetics, adhesion strength and viscosity of the resins with the load of hBN filler ranging from 9.2 to 25.7 vol.% (20-70 wt.%) were evaluated. It was found that the dielectric properties of resin containing SiO2 filler are inferior to that containing hBN. Also, the resins possessed lower CTE and the higher T-g when the hBN contents were high (> 15 vol.%) and the resin containing 25.7 vol.% hBN exhibited the largest thermal conductivity of 1.08 W/m K. Adhesion strength of the composite resins decreased with increase of hBN content and the adhesion strength on various substrates was found to be in the order of: alumina > Si wafer > eutectic PbSn solder.
A study of UV-curable epoxide resins containing thermal accelerator - Tertiary amines
(2008-02-01)
Chiang, Tzu Hsuan
;
Hsieh, T. -E.
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The individuals of tertiary amines, including imidazole (1-amine), 1,2-dimethylimidazole (2-amine), 2,4,6-tris(dimethylamino-methyl)phenol (3-amine), 1-methylimidazole (4-amine), and 2-methylimiclazole (5-amine), were added into UV-curable epoxide resins, respectively, and the effects on UV/thermal conversions, thermal properties and adhesion strengths for various types of substrates were investigated. According to the experimental results, the extent of effects of amines on physical properties was found in the order of. 3-amine > 4-amine > I-amine > 2-amine > 5-amine. The resin with 3-amine exhibited the highest glass transition temperature (Tg = 72.3 degrees C) value and the lowest coefficient of thermal expansion (CTE = 70.8 ppm/degrees C), which also exhibited the highest adhesion strengths on various substrates, on glass (greater than 199 kg/cm(2)), ITO (greater than 182 kg/cm(2)), PET (115 kg/cm(2)), and stainless steel (232 kg/cm(2)), and possesses great potentials for advanced opto-electronic applications. (C) 2007 Published by Elsevier Ltd.
Effect of tertiary amines on yellowing of UV-curable epoxide resins
(2007-12-01)
Chiang, Tzu Hsuan
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The work reported demonstrates that the yellowness of UV-curable epoxide resins can be improved by adding certain tertiary amines in appropriately determined amounts. According to the results of our experiments, 2.0 wt% benzoyl peroxide added to a resin effectively enhances the crosslinking density, and phenolic free radicals are produced during UV curing, which consequently induce yellowness via the reaction of oxygen and the free radicals. Imidazole (1-amine) and tertiary amines, including 1,2-dimethylimidazole (2-amine), 2,4,6-tris(dimethylaminomethyl)phenol (3-amine), 1-methylimidazole (4-amine) and 2-methylimidazole (5-amine), were chosen to be added to resins, and their effects on UV conversion and yellowness were investigated. According to the experimental results, tertiary amines in the resin can provide a certain degree of improvement in yellowness index (Delta YI) and color parameter (Delta E*(ab)) of the resin sample. Whatever the type of tertiary amine, it is found that the optimum content of amine in resin is 1.0 wt%. Also, among the studied amines, the 3-amine exhibits the highest UV reactivity and the best efficiency for yellowness improvement with values of Delta a*, Delta b*, Delta YI and Delta E*(ab) as low as -1.4, 6.23, 11.27 and 6.48, respectively. (C) 2007 Society of Chemical Industry.
Influence of acetic acid and ammonia catalyst on microstructure and properties of fluorinated polyimide-organosilicate hybrids
(2009-09-01)
Chiang, Tzu Hsuan
;
Liu, Szu-Ling
;
Lee, Shyh-Yang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
This work investigates the preparation, microstructure and thermal/electrical properties of fluorinated polyimide-organosilicate hybrids utilizing acetic acid and ammonia as the catalysts for sol-gel process to grow organosilicate filler particles. Nano-scale organosilicate was observed in the base-catalyzed hybrids, which was ascribed to the relative inertness of base catalysts in promoting the hydrolysis reaction. This postponed the formation of particles and hence smaller particle size. Electrical measurements found that the base-catalyzed hybrids possess lower dielectric constants (kappa = 2.40 at nominal Si content = 0.4 mol) due to the absence of polar groups and formation of silica xerogels with high porosity in the samples. In both hybrids, leakage current densities increase with the increase of Si content. However, leakage current density of base-catalyzed hybrid was higher than that of acid-catalyzed hybrid at the same Si content due to the smaller particle size and highly porous feature of organosilicate embedded in the base-catalyzed hybrids. (C) 2009 Elsevier B.V. All rights reserved.
Preparation of Silver Nanoparticles by Using Tripropylene Glycol as the Reducing Agents of Polyol Process
(2014-01-01)
Chiang, Tzu Hsuan
;
Wu, K. -D.
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Silver (Ag) nanoparticles were prepared by the polyol process using tripropylene glycol, 3-ethyl-3-oxetanemethanol, and polycaprolactone triol as the reducing agents and poly(vinylpyrrolidone) (PVP) with average molecular weights (M-w) of 10 000, 55 000, and 1 300 000 as the protective agent, respectively. It was found that the sizes of Ag particles were affected by the type of reducing agent, M-w of PVP, the concentration of PVP, reaction temperature, and time. The Ag nanoparticles as small as 34.4 nm were achieved when the reaction was conducted at atmospheric ambient and a temperature of 120 degrees C for 3 h by using tripropylene glycol as the reducing agent and 20 wt.% PVP with an M-w of 55 000. The nanoscale Ag particles with face-centered cubic structure exhibited a strong surface plasmon resonance peak at 350 nm in the UV-visible spectrum.
Preparation, microstructure, and property characterizations of fluorinated polyimide-organosilicate hybrids
(2008-11-01)
Chiang, Tzu Hsuan
;
Liu, Szu-Ling
;
Lee, Shyh-Yang
;
Hsieh, Tsung-Eong
;
材料科學與工程學系
Synthesis of organosilicate (orgSiO(2)) via sol-gel process utilizing tetraethoxysilane (TEOS) and diethoxydimethylsilane (DEDMS) as precursors was carried out in this work. Various amounts of orgSiO(2) were blended with fluorinated poly(amic acid) (PAA) to form the PAA-orgSiO(2) precursors and the fluorinated polyimide (PI)-orgSiO(2) (i.e., the HR1) thin-film hybrids were prepared via spin coating and curing treatments. The PI-orgSiO(2)-AP (i.e., the HR2) hybrids were also prepared by using the PAA-orgSiO(2) precursors containing the amine silane coupling agent, the 3-aminopropyltriethoxysilane (APTEOS). The effects of APTEOS on promoting the crosslinking between organic and inorganic components as well as the network formation were investigated. Fourier-transform infrared spectroscopy (FTIR) showed that the orgSiO(2) particles indeed formed in the hybrids due to the emergence of absorption bands corresponding to Si-O-Si and O-Si-O bonds. Nuclear magnetic resonance (NMR) analyses revealed that the Q(4) units or, the four bridging bond units, dominate the structure of orgSiO(2). Thermal analysis indicated that the implantation of orgSiO(2) in PI matrix may effectively improve the thermal stability of hybrids. Transmission electron microscopy (TEM) revealed the formation of nano-scale orgSiO(2) particles in both hybrids and the sizes of orgSiO(2) are relating to the Si content. In HR1 hybrids, the particles obviously coarsened when Si content was high while, in HR2 hybrids, the addition of APTEOS effectively suppressed the phase separation and the ultrafine orgSiO(2) particles as small as 5 nm could be achieved in the sample with high Si content. Dielectric measurements showed that the lowest values of dielectric constants are 2.40 and 2.20 for HR1 hybrid at intermediate Si content = 0.4 mol and HR2 hybrid with the highest Si content = 0.8 mol, respectively. The suppression of dielectric constants was attributed to the absence of polar Si-OH and Si-H(2)O functional groups as well as the completion of hydrolysis in the hybrids. Formation of silica xerogels in the hybrids should be another cause of dielectric constant decrement, as indicated by the porosity calculation. Experimental results implied that the control of orgSiO(2) size to imply the closed-form silica structure is essential to the low-dielectric constant properties of hybrids. Leakage current density measurement illustrated that no deterioration effect occurs due to the addition of orgSiO(2) nanoparticles in polymeric matrix and satisfactory electrical properties are preserved for the hybrids for advanced low-dielectric applications. (C) 2008 Elsevier Ltd. All rights reserved.