Abstract: An electronic module includes a wiring board having a first main surface and a second main surface on a back side of the first main surface, and a first semiconductor element and a second semiconductor element that are mounted on the wiring board. The first semiconductor element includes a first signal terminal and a second signal terminal. The second semiconductor element includes a third signal terminal and a fourth signal terminal. The wiring board includes a first signal line including a first signal trace disposed in a first conductor layer, a second signal line including a second signal trace disposed in a second conductor layer that is closer to the second main surface than the first conductor layer is, a first ground trace disposed in the first conductor layer, and a second ground trace disposed in the second conductor layer.

Abstract: A printed circuit board includes a printed wiring board, and a first element and a second element mounted on the printed wiring board. The printed wiring board includes a plurality of first signal lines and a plurality of second signal lines. The plurality of first signal lines each include a first main line, a first branch line, and a second branch line. The plurality of second signal lines each include a second main line, a third branch line, and a fourth branch line. The first branch line includes a first conductor pattern disposed in a first conductor layer. The second branch line includes a second conductor pattern disposed in the first conductor layer. The third branch line includes a third conductor pattern disposed in a second conductor layer. The fourth branch line includes a fourth conductor pattern disposed in the second conductor layer.

Abstract: A printed circuit board includes a printed wiring board, and a first element and a second element mounted on the printed wiring board. The printed wiring board includes a plurality of first signal lines and a plurality of second signal lines. The plurality of first signal lines each include a first main line, a first branch line, and a second branch line. The plurality of second signal lines each include a second main line, a third branch line, and a fourth branch line. The first branch line includes a first conductor pattern disposed in a first conductor layer. The second branch line includes a second conductor pattern disposed in the first conductor layer. The third branch line includes a third conductor pattern disposed in a second conductor layer. The fourth branch line includes a fourth conductor pattern disposed in the second conductor layer.

Abstract: Method and an apparatus for automatically moving the focal plane of the electron beam produced by a scanning electron microscope to the position of specimen surface. An auxiliary coreless coil of a low inductance is disposed close to the objective lens. The exciting current fed to the coil is varied to move the focal plane of the electron beam toward the optical axis. At each of discrete positions of the focal plane, a specimen is scanned with the electron beam. The resulting secondary electrons are detected by a detector. Individual output signals from the detector are compared to select the maximum signal. Then, only the objective lens is excited. The exciting current fed to the objective lens is modified to move the focal plane along the position closest to the specimen surface.

Abstract: There is disclosed a conical electromagnetic lens whose spherical aberration and chromatic aberration coefficients can be made small if the apex angle of the conical lens is small. The lens comprises a conical bobbin through which a beam of charged particles passes and a coil wound on the outer periphery of the bobbin. The number of turns of the coil per unit length along the axis of the lens is increased from the inlet end toward the exit end of the lens.

Abstract: A hyper-eutectic aluminum-silicon based alloy for castings has an essential disadvantage in its poor strength. The present invention provides an alloy comprised of 16-25% Si, 3.0-5.5% Cu, 0.2-0.8% Mg, 0.3-0.8 Mn, not more than 0.25% Ti and not more than 0.3% Fe to remove the above mentioned disadvantage. Another provided alloy containing 0.5-1.5% Zn in addition to the above mentioned ingredients not only removes the above mentioned disadvantage but also improves machinability. A still further provided alloy containing 0.3-2.0% Pb in addition to the first mentioned ingredients not only removes the above essential disadvantage but also improves machinability as well as additionally enhancing the wear resistance. In the disclosed alloys the content of iron as one of the impurities is restricted to a low level, because iron destroys the effect of the invention to remove said disadvantage.

Abstract: The present invention relates to a method of manufacturing a metal-impregnated body by immersing a porous ceramic or ceramic powder in a solution containing a chemical compound having an OH radical selected from the group consisting of water and aqueous solutions of methanol, ethanol, butanol, acetone, acetic acid and ammonium hydroxide; drying and molding it into a porous body; and then impregnating said porous body with a molten metal.

Abstract: The present invention relates to a method of manufacturing a metal-impregnated body in which a porous body is immersed under sub-atmospheric pressure in a molten alloy for impregnation with said alloy or a porous body is immersed under elevated pressures produced by various gases, the pressure then being reduced to normal level, after which the porous body is introduced together with a molten alloy into a metal mold, in which said molten alloy is impregnated into said porous body. The porous body is then separated from said molten alloy.