Graphite is an efficient and affordable filler for polymer composites, allowing the control of thermal conductivity. In comparison to other thermally conductive fillers, graphite is lightweight and flexible but affords anisotropic thermal conductivity. Herein, the control of thermal conductivity of graphite‐containing polymer composite sheet using spherical polymer particles as additional fillers is described. The thermal conductivity in the through‐plane direction (λt) of the composite sheet is enhanced by varying the composition ratio of the two fillers (flaky graphite and spherical particles), and optimizing the forming temperature and pressure. Graphite‐containing (25 wt%) polymer composite sheet formed by compression at 150 °C and 10 MPa exhibits λ t value of 0.66 W/m K. Upon mixing of polystyrene microspheres, λ t is successfully increased. The maximum value of thermal conductivity for a composite sheet with 35 wt% of graphite and 50 wt% of spherical particles is 7.51 W/m K, at 180 °C and 10 MPa. The graphite‐containing polymer matrix forms a sequentially connected network‐like structure in the composite sheet. Excess polymer microspheres lead to the formation of void structures inside the composite sheet, reducing the thermal conductivity. Thermo‐camera observations proved that the composite sheets with higher λ t value showed comparably high heat radiations. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 607–615

As Wafer Level Fan-Out Packaging (WLFO) designs continue to evolve, higher pattern densities for Cu lines and interconnects continue to increase while thickness continues to decrease. As Cu densities increase, the patterning resolution of the RDL dielectric needs to shrink to allow increased bump density. The higher Cu density in turn requires enhanced dielectric performance to minimize Cu migration, whilst utilizing lower temperature and shorter cure times which result in lower levels of wafer warpage. Minimizing mechanical stress, continues to be a critical function of the RDL dielectric. Warpage leads to poor yields, distorting the planarity of the package and ultimately leading to stress induced failure from cracking and delamination. Reduction of the thermal budget is the primary means of reducing mechanical stress in WLFO designs. The amount of Cu in the package continues to increase. Differences in thermal expansions of such and the dielectric increase with temperature. Further, conventional solder reflow processes and set points will continue to be used, therefore the RDL dielectric must continue to be thermally and mechanically stable but capable of being cured at lower temperatures, 180–200 °C to minimize overall mechanical stresses from thermal expansion. We present a novel polyamide based RDL dielectric, KMRD, designed to achieve current and future WLFO design requirements. KMRD is a low temperature curable, aqueous (2.38%TMAH) developable dielectric capable of meeting industry standards for mechanical and electrical requirements, with a high level of reliability while utilizing a single stage cure at 185 °C. KMRD provides clear advantages over incumbent materials, with low temperature cure, improved pattern resolution, wide process latitudes, superior adhesion, chemical compatibility, and cost benefits using standard processing equipment and chemistry.

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: This study aims to investigate the effect of silhouette on impressions of fashion coordinate. In order to separate the effect of silhouette from that of the other factors, silhouette images and scrambled images were prepared for 25 ladies fashion photographs. Fourteen participants viewed the two types of images and the original images and rated the impressions of each image with 5 pairs of affective words and 7 point scales. The result showed that the ratings on silhouette images and that on original images were moderately correlated for about half of the participants with three affective words, 'unique-common', 'adultlike-childlike', and 'like-dislike'. On the other hand, the effect of silhouette was considerably weaker with two affective words, 'active-modest' and 'light-heavy'.

Chiral glutamide-derived lipids form self-assembled fibrous molecular gels that can be used as HPLC organic phases. In this study, HPLC separation efficiency was improved through the addition of branched amphiphilic glutamide lipids to the side chains of a terminally immobilized flexible polymer backbone. Poly(4-vinylpyridine) with a trimethoxysilyl group at one end was grafted onto the surface of porous silica particles (Sil−VP15, polymerization degree = 15), and the pyridyl side chains were quaternized with a glutamide lipid having a bromide group (BrG). Elemental analysis indicated that the total amount of the organic phase of the prepared stationary phase (Sil−VPG15) was 38.0 wt%, and the quaternization degree of the pyridyl groups was determined to be 32.5%. Differential scanning calorimetric analysis of a methanol suspension of Sil−VPG15 indicated that the G moieties formed a highly ordered structure below the phase transition temperature even on the silica surface, and the ordered G moieties exhibited a gel-to-liquid crystalline phase transition. Compared with a commercially available octadecylated silica column, the Sil−VPG15 stationary phase showed high selectivity toward polycyclic aromatic hydrocarbons, and particularly excellent separations were obtained for geometrical and positional isomers. Sil−VPG15 also showed highly selective separation for phenol derivatives, and bio-related molecules containing phenolic groups such as steroids were successfully separated. These separation abilities are probably due to multiple interactions between the elutes and the highly ordered functional groups, such as the pyridinium and amide groups, on the highly ordered molecular gel having self-assembling G moieties.