Two types of thermotropic liquid crystalline polymers (fully-aromatic type, VA and semi-aromatic type, NE) were filled with glass fiber (GF) and carbon fiber (CF) to produce composite materials. These composite materials were processed using a capillary rheometer under different pressure and cooling temperature conditions to prepare four types of strands, and their dynamic viscoelastic properties were measured at 1 and 104Hz. The results of the measurement were as follows. For unfilled liquid crystalline polymers, VA and NE, the storage modulus (E′) and loss modulus (E″) were markedly affected by the strand processing conditions, with both E′ and E″ decreasing with increasing frequency. For both GF- and CF-filled VA systems, E′ and E″ increased with increasing fiber content. The degree of the influence of the processing conditions on viscoelastic properties of CF/VA was higher than that for the GF/VA system. E′ and E″ of the CF- filled system also showed a larger fiber-content dependency than the GF-filled system. In both systems, E′ and E″ showed little difference in their values measured at 1 and 104Hz, suggesting that their frequency dependency was small. In GF- and CF-filled NE systems, both E′ and E″ showed a small frequency dependency. When comparing the fiber content dependency on viscoelastic properties for both systems at 1 and 104Hz, that for the GF/NE system was higher than for the CF/NE system. The dependency of E′ and E″ on processing conditions in the fiber-filled NE systems showed different behavior from those of the fiber-filled VA systems, i. e. the degree of the influence of the processing condition on E′ and E″ of the GF/NE system was higher than that for the CF/NE system.
The glass transition temperature (T_g) of the VA and NE systems determined from their tan δ curves at 1Hz were larger than those by the DSC method. Fiber content dependency of T_g for the GF- and CF- filled VA systems were different from those of the GF- and CF-filled NE systems. In all the systems, the inflection points (T_c) of the tan δ curves at 104Hz were larger than the corresponding T_g at 1Hz. Both unfilled and fiber-filled VA and NE systems showed processing dependency for their T_g and T_c values.

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The thermal stability and recyclability of Polycarbonate resin (PC) composites filled with silica particles which are surface-treated with polyhydric phenol agents has been investigated. The composites were evaluated after molding 4 consecutive times. For the composites containing 1.5wt% silica particles treated with polyhydric phenol, the number-average molecular weight (M_n) of PC in the composites, measured by gel permeation chromatography, decreased from 24300 to 21800 after 4 injection molding cycles, while the unfilled PC resin control decreased to 21000.
These results suggest that the PC molecule depolymerized during the injection molding process due to the thermal energy and stress. On the other hand, we found that the surface treatment of silica particles with polyhydric phenol reduced the decrease in PC Izod impact strength to 1/5 that of the neat PC resin. In addition, we studied the effects of multistage surface treatment of silica particles using two phases and three phases with benzophenone, silane-coupling agents. Three phase multistage treated silica particles resulted in higher M_n retention than those containing a single phase with polyhydric phenol.
The magnitude of the activation energies (ΔE) related to the thermal degradation of the composites were evaluated by thermo-gravimetry. ΔE increased in the following order: neat PC, composite with the two-phase multistage and that with the three-phase multistage.
These findings suggest that the addition of multistage surface-treated particles in PC improved the stability of PC composites. This implies that surface treatment may be an effective method in the recycle of PC resin composites.

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A practical method for predicting gold-wire deformation in the transfer molding process of semiconductor devices has been developed. In this study, a BGA (Ball Grid Array) package having 156 wires with uniform dimensions was used. Horizontal, dimensionless, and deformed configurations of gold wires were found to be the same as those of elastic straight beams under the conditions of end supports and center load. An empirical model having parameters of the resin velocity component perpendicular to the center of each wire, resin flowing time at the center of each wire, and apparent resin viscosity in a mold cavity was formulated. Using this model, maximum values of the deformation of every gold wire in the package at several molding conditions were calculated accurately.

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