Abstract: In a centrifugal type blower unit, a diameter of an air suction port is set to be larger than a minimum inner diameter of a centrifugal fan, and a slanting portion is formed in each blade of the centrifugal fan at a side of the air suction port so that an inner radius dimension of the centrifugal fan is increased toward the air suction port. Therefore, it can prevent sub-flow air which is sucked into the centrifugal fan from an end side of the blades in an axial direction from interfering with main-flow air which is sucked into the centrifugal fan from an inner radius side of the blades. Thus, the blower unit can reduce second noise generated therefrom without greatly reducing air-blowing capacity.

Abstract: In a tip portion structure basically having a substrate, a plate spring, and a ground block, the substrate is attached to a signal line on a back surface of the substrate and is contacted on the tip with the signal electrode of the DUT placed on a device stage. The plate spring is made of a resilient material, placed on the front side of the substrate, and positioned to apply a pressure to the substrate. The ground block is positioned between the signal line and the device stage functioned as a ground electrode of the DUT. Alternatively, the tip portion structure further may have a ground plate or a ground surface formed of a conductive thin plate covering entirely the front surface of the substrate, and shaped to surround the signal line in cooperation with the ground block . A plurality of the signal lines may be arranged in parallel on the same plane of the substrate.

Abstract: In a high-frequency probe having a detachable end according to the present invention, parts relating to replacement of an end unit are three parts, that is, an end unit, a probe body, and a pressure block. The end unit comprises a coaxial cable, two slender plate-like ground plates. The coaxial cable is linear in the direction of the end of the high-frequency probe. The ground plates sandwich the coaxial cable. The probe body has an end unit support surface, a circuit board, an end unit arrangement surface and an end part guide. The end unit support surface forms a perpendicular surface used for fixing the end unit to a predetermined position in the end side of the central block in a central part of a surface of the body block. The circuit board connects the end unit to a coaxial connector. The end unit arrangement surface forms a plane in an end side of the body block. And further the guide groove positions and fixes the ground plate in the end part.

Abstract: A process for manufacturing a high frequency multichip module includes a reception inspection step which includes steps of preparing a vertical-type probe, setting the high frequency bare chip on a device stage, and measuring high frequency characteristics of the high frequency bare chip using the vertical-type probe. The prepared vertical-type probe has a center conductor and ground conductors arranged at both sides of the tip portion of the center conductor in the vertical direction in which the probe is pressed to electrodes of the high frequency bare chip. The high frequency bare chip has a ground electrode disposed at the opposite side of the chip from the signal electrodes on the upper surface of a device stage. Then, only a good product is fed to the next step. After the reception inspection, the process goes to a component mounting step.

Abstract: In a centrifugal blower in which the outer periphery of an intake opening is arranged outside of the inner edge of a main blade, a large number of sub blades are provided in the intake opening at a location corresponding to the main blade. The sub blades lead the secondary air flowing from an outside area of the intake opening to a rotating direction of a centrifugal multi blade fan. Thus, the secondary air flows from the sub blade to the main blade smoothly, thereby increasing a secondary air flow amount and reducing air flow noise.

Abstract: A scroll casing of a centrifugal blower holds a centrifugal fan therein and defines an air passage around the centrifugal fan. The scroll casing has a scroll starting position at the most upstream portion of the air passage, a scroll ending position at a downstream portion thereof, and an air outlet at the most downstream side thereof. Between the scroll ending position and the air outlet, the scroll casing has a warped face and a guide face. Accordingly, an air flow flowing apart from the fan and an air flow flowing close to the fan are prevented from mixing with each other. As a result, interference between the air flows and blades of the fan is generally prevented, whereby noise is decreased.

Abstract: A bell-mouth ring is formed with a casing to be disposed proximately at an outer radial side of a shroud. The bell-mouth ring has a deflection wall surface for deflecting a flow of air blown out radially outwardly from the centrifugal multi-blade fan and further flowing radially inwardly toward the rotation axis along an inner wall surface of the casing, toward the driving means. In this way, it is possible to suppress air from flowing backward to a suction port through a gap between the shroud and the bell-mouth ring. Accordingly, it is possible to reduce the noise generated by an interference of the air sucked from the suction port with the air flowing backward or by the turbulence of the air flow which is generated in the gap.

Abstract: An inner diameter (d.sub.2) of a centrifugal-type multiple-vane fan at a side where the motor is inserted (i.e., the insertion side) is larger than an inner diameter (d.sub.1) of the centrifugal-type multiple-vane fan at a side where the motor is not inserted (i.e., the non-insertion side), such that the ratio of a difference between an outer diameter (D) and the inner diameter (d.sub.2) of the centrifugal-type multiple-vane fan of the insertion side to a difference between the outer diameter (D) and the inner diameter (d.sub.1) of the centrifugal-type multiple-vane fan of the non-insertion side is in a range of 0.6-0.95. Thus, a centrifugal-type blower having the centrifugal-type multiple-vane fan can obtain a desired air volume while maintaining a small size of the centrifugal-type blower.