A multilayer optical printed wiring board with a cube-core structure was developed for high-density optical interconnections. A fabricated multilayer optical printed wiring board with this cube-core structure has optical-coupling efficiency 2.7 dB higher than one without this structure. A fabricated optical interconnection model successfully demonstrated 10-Gbit/s/channel operation. These results show that the advantage of this cube-core structure is that it provides high optical-coupling efficiency in a high-density multilayer optical printed wiring board.
Abstract Cyanoacetylene can be polymerized from vapor state onto an inactive surface of substrate at a temperature as low as 200°C. The structure and electric conductivity of these cyanoacetylene products have been investigated.
Abstract Thermal behavior of fluorine‐containing bismaleimides was investigated by differential scanning calorimetry and the effects of introducing fluorine groups on thermal behavior and properties of cured products were discussed. The melting point was lower and the polymerization temperature was higher with increasing fluorine content. This decrease in polymerization reactity of fluorine‐containing bismaleimide was explained by the stabilization energy of the double bond or the bismaleimide molecule itself as calculated by the MNDO or MM method. Thermal polymerization of the double bond was interpreted by an autocatalytic reaction mechanism in which the activated biradical product accelerated the radical propagation. It was found that the fluorine‐containing cured product had good thermal stability and a low dielectric constant.
Abstract New alternating copolymers are obtained between ethyleneimine which is nucleophilic and α, β-unsaturated acids that are electrophilic. The alternating structure was identified by IR, NMR, and elemental analyses. A reaction mechanism is elucidated in the light of polymer structure which involves a ring-opening reaction of ethyleneimine and a hydrogen transfer to the double bond of α, β-unsaturated acid which is similar to the Michael-type addition reaction. A terpolymer from ethyleneimine, methacrylic acid, and phthalic anhydride was also obtained. It indicates that the two pairs of acid/base copolymer species are cross-propagated and also that the mechanisms involved in both the polymerization of ethyleneimine with dicarboxylic anhydride and of ethyleneimine with a, 0-unsaturated acid are basically similar to each other.
Calcium phosphates with metal ions are expected to show interesting characteristics, such as catalytic activity, as well as high ability to adsorb organic substances. We assumed that the organic substances adsorbed on calcium phosphates could be decomposed by treatment with hydrogen peroxide (H2O2) if the catalytic activity for the decomposition of H2O2 can be introduced to calcium phosphates. We synthesized hydroxyapatite (HAp) containing Ni or Co ions, and octacalcium phosphate (OCP) containing Ni, Co or Mn ions. The HAp containing Co ions and the OCP containing Co or Mn ions showed catalytic activity for the decomposition of H2O2.
