Abstract: The invention relates to a wiring circuit board including an electronic device disposed in a hole of the wiring circuit board; a resin filling the hole such that the electronic device is embedded in the resin; a wiring layer formed on the resin; and an interface between the resin and the wiring layer. This interface has a roughness in a range of 2-6 &mgr;m in terms of ten-point mean roughness.

Abstract: The invention relates to a wiring circuit board including an electronic device disposed in a hole of the wiring circuit board; a resin filling the hole such that the electronic device is embedded in the resin; a wiring layer formed on the resin; and an interface between the resin and the wiring layer. This interface has a roughness in a range of 2-6 &mgr;m in terms of ten-point mean roughness.

Abstract: An embedding resin embeds an electronic part in an object and has a dielectric constant of about 5 or less and tan&dgr; of about 0.08 or less.

Abstract: An embedding resin that is caused to assume any base color selected from among black, blue, green, red, orange, yellow, and violet is used for embedding an electronic part in an insulating substrate. The embedding resin preferably contains at least one coloring agent selected from among carbon black, a phthalocyanine-based pigment, an azo pigment, a quinoline-based pigment, an anthraquinone-based pigment, a triphenylmethane-based pigment, and an inorganic oxide.

Abstract: The present invention provides a wiring board in which electronic components are embedded by means of an embedding resin which attains a high mounting density of the electronic components in the wiring board, which exhibits excellent electrical properties such as insulating property, which prevents random reflection of light, and which reduces non-uniformity in color of the resin during curing thereof. The present invention includes a wiring board in which electronic components are embedded by use of an embedding resin having a dielectric constant of less than or equal to about 5 and tan &dgr; of less than or equal to about 0.08. The embedding resin preferably contains carbon black in an amount of less than or equal to about 1.4 mass %. Moreover, the embedding resin preferably contains at least a thermosetting resin and at least one inorganic filler.

Abstract: A wiring board includes a substrate having an opening, and an electronic part placed in the opening, wherein a space left in the opening is filled with an embedding resin having a base color tone selected from black, blue, green, red, orange, yellow, and violet.

Abstract: In an embedding resin for embedding electronic parts, after a substrate in which a copper layer is formed on a cured product of the embedding resin is subjected to a pressure cooker test, the copper layer has a peeling strength of at least 588 N/m (0.6 kg/cm), wherein the conditions of the pressure cooker test are 121° C., 100% by mass humidity, 2.1 atm and 168 hours, and the measurement method of the peeling strength is according to JIS C 5012, and the width of the copper layer is 10 mm.

Abstract: A paste for filling through-holes of a printed wiring board contains 100 parts by weight of an epoxy resin composition containing 90 to 99.5 parts by weight of an epoxy resin and 0.5 to 10 parts by weight of a curing agent; and (B) 500 to 1000 parts by weight of a metallic filler having an average particle size of 0.5 to 20 &mgr;m. The paste has a viscosity of not higher than 20,000 poise at 25° C. and a volatile content of not more than 1.0% when heated in a filling step. The paste exhibits such shrink-resistance properties that when a first cured resin obtained by heating in a filling step is re-heated and cooled in a solder reflow step to obtain a second cured resin, the shrinkage percentage of the first cured resin to the second cured resin in the longitudinal direction of the through-hole is not greater than 0.1%.

Abstract: Insert 1 comprises thin substrate made by cold-rolling, and two bonding alloy layers formed by plating on the upper and lower surfaces of substrate, respectively. Both layers is extremely thin, and is made of an alloy having a melting point lower than that of substrate. Insert 1 is used to achieve liquid phase diffusion bonding of first and second base metals. Insert 1 is interposed between first base metal and second base metal. Then, insert 1 and base metals are clamped together with a pressure of, for example, 0.5 kgf/mm.sup.2, and are placed in a atmosphere of a low pressure of about 10.sup.-4 Torr and heated to the melting point of alloy layers or to a temperature above this melting point but below the melting points of substrate and plates.

Abstract: In longitudinally seam-welding a pipe-blank for welded steel pipe from the inside along a groove by the GMA welding process which comprises using direct electric current supplied to a plurality of consumable electrodes in tandem through at least one cable as the welding current, at least two even-numbered consumable electrodes are used, half of said consumable electrodes being connected to said direct current so as to be positive in polarity and the remaining half of said consumable electrodes being connected to said direct current so as to be negative in polarity, to enable lines of magnetic force produced by said direct electric current for welding flowing through said at least one cable introduced into said pipe-blank to cancel each other, thereby preventing magnetization of said pipe-blank and the resulting magnetic arc blow of the welding arc.

Abstract: In longitudinally seam-welding a pipe-blank for welded steel pipe from the inside along a groove by the reverse-polarity GMA welding process comprising using direct electric current supplied to a consumable electrode through a cable as the welding current with said consumable electrode as the anode, the direction of said direct electric current for welding flowing through said cable introduced into said pipe-blank is set in the same direction as that of welding, thereby preventing occurrence of a magnetic arc blow of the welding arc from said consumable electrode toward the upstream side of the welding direction, i.e., in the opposite direction to that of welding.

Abstract: After longitudinally seam-welding a pipe-blank for welded steel pipe from the inside along a groove by the arc welding process which comprises using direct electric current supplied to a consumable electrode through a cable as the welding current, the polarity of said consumable electrode applied for said longitudinal seam-welding is switched over to the opposite polarity, an arc from said consumable electrode is ignited again on a tab plate attached to the end of said pipe-blank on the completion side of said longitudinal seam-welding to cause a direct electric current for eliminating magnetism to flow through said cable in the opposite direction to that of said direct electric current for welding, thereby eliminating residual magnetism in said pipe-blank produced by said direct electric current for welding flowing through said cable introduced into said pipe-blank during said longitudinal seam-welding.