Abstract: In order to manufacture an epitaxial wafer having satisfactory flatness over its entire surface, epitaxial layers are experimentally grown upon actual wafer samples under various different layer formation conditions, the thickness profiles are measured over the entire surfaces of these wafers before and after growth of the layers, and, from the differences thereof, layer thickness profiles over the entire areas of the epitaxial layers under the various different layer formation conditions are ascertained and stored. Thereafter, the thickness profile of a substrate wafer is measured over its entire area, this is added to each of the layer thickness profiles under the various different layer formation conditions which have been stored, and the planarities of the manufactured wafers which would be manufactured under these various different layer formation conditions are predicted.

Abstract: The present invention provides a dart having a durable and break-resistant structure. A dart in accordance with an embodiment of the present invention has, in order from the front thereof, a tip, a barrel, a shaft, and a flight. At the rear of the shaft, a cap-receiving portion having a diameter smaller than that existing elsewhere is formed, this cap-receiving portion being capable of receiving a cap-like portion of the flight. At the front end of the flight, a hollow cylindrical cap-like portion containing a hole for attachment to the cap-receiving portion of the shaft is formed. The shaft and the flight are connected to each other by a sliding engagement method.

Abstract: A multiconductor plug (10) has exposed electrodes (11a through 11e) on a shaft portion (14) and an electrode (11f) located at an annular flat portion of a flange portion (15) perpendicular to an axial direction. A multiconductor jack (20) has a casing (21) forming a space capable of being occupied by the shaft portion (14) of the multiconductor plug (10), electrically conductive terminals (23a through 23e) that come into electrically conductive contact with the electrodes (11a through 11e) of the shaft portion (14) of the multiconductor plug (10), and an electrically conductive terminal (23f) having a contacting portion (23f1) for making electrically conductive contact with the flat electrode (11f) perpendicular to the axial direction and an elastic portion (23f3) that extends in the axial direction. The contacting portion (23f1) of the electrically conductive terminal (23f) presses against the electrode (11f) as a result of elastic forces parallel to the axial direction.