Browsing by Author "LIU, KC"

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DEVELOPMENT OF TEMPERATURE-STABLE THICK-FILM DIELECTRICS .3. ROLE OF GLASS ON THE MICROSTRUCTURE EVOLUTION OF A THICK-FILM DIELECTRIC
(1991-09-01)
CHIOU, BS
;
LIU, KC
;
DUH, JG
;
CHUNG, MC
;
電子工程學系及電子研究所
Glass phase plays an important role in the characteristics of thick-film microelectronics. A dielectric system in BaTiO3 and SrTiO3 containing PbO, B2O3, SiO2, and Al2O3 glass constituents is investigated. Microstructure evolution and phase distribution after thermal aging are studied with the aid of electron microscope and X-ray diffractometer. It is observed that the phases in 40 vol% BaTiO3-25 vol% SrTiO3-35 vol% glass thick-film dielectric are not altered after 500-degrees-C aging for 480 h. The variation in surface morphology after long time aging is attributed to the precipitation of heavy metal component from the glass which acts as a diffusion species and then dissolves the crystalline phase during firing. The presence of glass in the dielectric enhances the formation of solid solution (Ba(x)Sr1-x)TiO3 and results in the broadening of the Curie peak.
INTERMETALLIC FORMATION ON THE FRACTURE OF SN/PB SOLDER AND PD/AG CONDUCTOR INTERFACES
(1990-06-01)
CHIOU, BS
;
LIU, KC
;
DUH, JG
;
PALANISAMY, PS
;
電控工程研究所
TEMPERATURE CYCLING EFFECTS BETWEEN SN/PB SOLDER AND THICK-FILM PD/AG CONDUCTOR METALLIZATION
(1991-03-01)
CHIOU, BS
;
LIU, KC
;
DUH, JG
;
PALANISAMY, PS
;
電控工程研究所
Thermal cycling effects on solder joint between thick film mixed bonded conductor and Sn/Pb solder are investigated. Microstructural evolution of the interfacial morphology, elemental, and phase distribution are probed with the aid of electron microscopy and x-ray diffraction. Microstructural analysis reveals the formation of intermetallic compounds Pd3Sn, Pd2Sn, Pd3Sn2, PdSn, Pd3Pb, Ag5Sn, and Ag3Sn, after thermal cycles from -55 to + 125-degrees-C. A transverse crack is observed across the joint from the conductor/substrate interface to the conductor/solder interface, which results in the failure of the joint. The microstructural analysis and stress analysis reveal that the transverse crack is initiated by the microcracks at the glass penetrated region of the substrate and propagates under a tensile stress due to the solder shrinkage. An appropriate joint geometry and a materials system with good interface strength and with negligible thermal expansion mismatch are important in the enhancement of the life time for the solder joints in thick film microelectronics.