Abstract: This invention relates to a granular phenolic resin forming material. Grains are obtained by pulverizing a hardened phenol resin or epoxy resin, particularly a waste, having aromatic rings. The grains are heated to react with a phenolic substance, to solubilize at least surfaces thereof, whereby the grains are made formable again. The pulverized, hardened grains and the phenolic substance, preferably a phenol, are mixed in the ratio of 100/10 to 100/90. An acid catalyst may be used, as necessary, in a quantity not exceeding 9 parts. A preferred reaction temperature is 80.degree. to 180.degree. C. at atmosphere pressure. The forming material of this invention may be formed with hexamine compounded therewith.

Abstract: Printed circuit board, provided with conductive pattern on one side or both sides of the board and through-holes, has conductive materials being inserted in its through-holes, the conductive material being metallically connected with the conductive pattern.The printed circuit board is manufactured in such a manner that by inserting conductive material to the through-hole, bending end portion of the conductive material laterally toward conductive pattern, applying ultrasonic welding to the bent end portion of the conductive pattern so as to make the end portion metallically connected to the conductive pattern.

Abstract: A method of forming an embossing pattern in which, on the working surface of the first of a pair of steel rolls, an acid-resistant coating corresponding to the pattern intended for embossing is formed on the positive or convex form, and on the working surface of the second steel roll, an acid-resistant coating is placed thereover except on the part that will be the negative or concave form, where the second steel roll is identical in size to the first and symmetrical thereto; and then the surface part not covered by the acid-resistant coating on each roll is corroded by etching to form a concavity and convexity on the respective working surfaces thereof, causing the predetermined side etching to take place on each side surface of the concavity and convexity, so that an appropriate clearance may be formed between the side surfaces of the concavity and the convexity facing each other, as both working surfaces are coincidentally fitted together.