Abstract: Lead-free solder balls having a good surface appearance with no appreciable surface defects such as seams and shrinkage cavities comprises an alloy having a composition consisting essentially of about 4.0% to about 6.0% by weight of Ag, about 1.0% to about 2.0% by weight of Cu, and a balance of Sn, and they have a diameter of from 0.05 mm to 1.0 mm. The solder balls can be produced by forming a molten alloy having the above-described composition into solidified balls having a diameter of from 0.05 mm to 1.0 mm using the surface tension of the molten alloy.

Abstract: A drinking receptacle cover to be removably applied to an opening of a receptacle main body. This cover has on its top plate a drinking spout which can be shut off and a negative pressure relief valve. The spout contains a drinking spout main body which protrudes from the top plate and has a channel; a drinking spout portion which is fitted on the drinking spout main body to be shiftable in the axial direction so as to open and close the channel; and a drinking spout cap which can be removably applied to the drinking spout portion; and the channel can be opened and closed by the shift of the drinking spout portion which occurs with fitting and removal of the drinking spout cap.

Abstract: A thermally insulated double-walled synthetic resin container having a thermal insulator layer filled with a low thermal conductivity gas, wherein the inner container and the outer container are formed from a chemical resistant resin, a hole portion is provided at the enter of the bottom wall of the outer container, this hole portion is sealed by a sealing panel formed from chemical resistant resin; a protrusion portion is formed on the thermal insulator layer side of the bottom central portion of the outer container and a depression portion aligned with the center of the protrusion portion is formed on the reverse side of this protrusion portion; or a metallic thin film layer is formed on the surfaces facing the thermal insulator layer aside from the area around the mouth; as a result of which the thermally insulated double-walled synthetic resin container is provided with exceptional thermal insulation capabilities and strength.

Abstract: A thermally insulated double-walled synthetic resin container having a thermal insulator layer filled with a low thermal conductivity gas, wherein the inner container and the outer container are formed from a chemical resistant resin, a hole portion is provided at the enter of the bottom wall of the outer container, this hole portion is sealed by a sealing panel formed from chemical resistant resin; a protrusion portion is formed on the thermal insulator layer side of the bottom central portion of the outer container and a depression portion aligned with the center of the protrusion portion is formed on the reverse side of this protrusion portion; or a metallic thin film layer is formed on the surfaces facing the thermal insulator layer aside from the area around the mouth; as a result of which the thermally insulated double-walled synthetic resin container is provided with exceptional thermal insulation capabilities and strength.

Abstract: A tunnel-type reflow furnace containing a preliminary heating zone and a main heating zone is disclosed. In the furnace, at least two pairs of infrared heaters are disposed on both the top and bottom of a tunnel providing a pathway for the transfer of an article to be heated, and the infrared heaters are of a gas blowing type. In a preferred embodiment, a gas-blowing nozzle that is freely adjustable in the direction of gas blowing is provided between infrared heaters on both the top and bottom of the tunnel. This furnace allows the heating profile to be easily changed in accordance with a specific use. It is also capable of efficient and uniform heating of a printed circuit board even if it carries many components at high density. As a result, the furnace ensures reliable soldering of the circuit board.

Abstract: A solder paste comprises a solder paste portion containing powdered solder and metallic spheres which are made of a material having a higher melting point than the solder paste portion and whose surface can be wet by molten solder. The metallic spheres have a diameter of 0.07-0.3 mm. The metallic spheres can comprise a single metal or two metals, one of which forms the center of the sphere and the second of which is plated on the surface of the first.