Abstract: An object is to provide a composite board of plaster and inorganic fiber excellent in fire resistance, provided with sound-absorbing property, which is absent from a plasterboard, and heat insulating property, light in weight, and high in dimensional stability to humidity change. The composite board of plaster and inorganic fiber is provided, which is characterized in that the proportion of the inorganic fiber ranges 20 to 70% by weight with respect to the total weight of the composite board. Since the composite board of the present invention contains inorganic fiber, it becomes a lightweight plasterboard and excellent in sound absorbing property. In addition, since the composite board of the present invention uses plaster, which is excellent in dimensional stability, as a binder, it is excellent in dimensional stability to humidity change compared to a rock wool decorative sound-absorbing board using a large amount of starch as a binder.

Abstract: A method and apparatus for inspecting wirings of an electronic circuit substrate to detect a defect in the wiring and for enabling correction thereof. The inspection method and apparatus include electrostatically coupling at least one electrode to a wiring pattern, applying a time varying voltage between the electrode and wiring pattern at different locations so as to detect a current flow and determine a defect by a variation in the detected current flow at the different locations and a portion of the defect. A defect in the form of a disconnected or half-disconnected point of the wiring may be corrected by supplying a solution of a metal complex to the disconnected or half-disconnected point, heating the solution and end point areas of the disconnected or half-disconnected point by laser light and precipitating a metal thin film establishing a connection of the wiring.