Abstract: A multi-hole tube extrusion die comprises a female mold die having a flat opening and a mandrel having comb-teeth-like molding portions arranged in the opening. A heated material is extruded between the female mold die opening and the comb-teeth-like molding portions of the mandrel to form a tube having a multi-plicity of holes. An interval between each of the comb-teeth-like molding portions at the opposite ends of the mandrel and the comb-teeth-like molding portion adjacent to the outermost comb-teeth-like molding portion is set to be smaller than an intervals between the female mold die opening and each of the outermost comb-teeth-like molding portions and to be larger than an interval between adjacent ones of the other comb-teeth-like molding portions. Additionally, the outermost comb-teeth-like molding portions are larger in width than the other comb-teeth-like molding portions.

Abstract: A low-temperature burnt conductive paste prepared by dispersing, in an organic vehicle, a base material comprising 50 to 95% by weight of a powder of at least one conductive material selected from the group consisting of a copper alloy, a copper oxide and a copper alloy oxide and 5 to 50% by weight of a glass powder having a softening point of 300.degree. to 600.degree. C. and a coefficient of thermal expansion of 6 to 13.times.10.sup.-6 .degree.C..sup.-1, and a method of manufacturing a printed circuit board using this paste.

Abstract: This invention provides an aluminum enamel board having an electrically insulating glass layer formed on an Al-Si alloy plate containing at least 5 wt % of Si or a composite metal plate having an aluminum or alloy layer formed on at least one side of a metal plate made of a metal other than aluminum. Since the Al-Si alloy plate containing at least 5 wt % of Si or a composite metal plate having the aluminum or aluminum alloy layer is used as a board, the adhesion strength between the metal plate and the electrically insulating glass layer can be increased. At the same time, a predetermined material is used to form the electrically insulating glass layer, thereby minimizing a difference in thermal conductivity and thermal expansion coefficient between the electrically insulating glass layer and the metal plate. This improves the heat conduction characteristics of the board and prevents warping of the board.

Abstract: This invention relates to the method and apparatus for improving the cast ingot, cast in a continuous casting equipment which is commonly called a "belt-and-wheel" system wherein a casting wheel and a metallic belt are employed, by applying a light reduction to the cast ingot to give elongation under compressive stress during the process wherein the curvature of the cast ingot changes as the cast ingot travels from the exit of a casting wheel.More particularly, this invention relates to cast ingot quality improvement method and apparatus in a continuous casting which aims at preventing cracks which were liable to occur on the groove bottom side of the ingot cast by the said continuous process; similarly it also aims at crushing blow holes which tended to concentrate on the groove bottom side the cast ingot.