Abstract: A magnetic-disk glass substrate capable of suppressing turbulence of air flow in a vicinity of an outer circumferential side edge portion of the magnetic disk and suppressing disk flutter is provided. This magnetic-disk glass substrate includes a pair of main surfaces, a side wall surface formed on an outer circumferential side edge surface, and chamfered surfaces interposed between the side wall surface and the main surfaces, respectively. The side wall surface has a roundness of 1.5 ?m or less. A difference in radius between an inscribed circle and a circumcircle of a plurality of outlines of the side wall surface at a plurality of positions that include a central position of the magnetic-disk glass substrate in a thickness direction and are different from each other in the thickness direction is 5 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular center hole a pair of main surfaces and an edge surface. The edge surface has a side wall surface and chamfered surfaces interposed between the side wall surface and the main surfaces, and a roundness of an edge surface on an outer circumferential side is 1.5 ?m or less. Also, a midpoint A between centers of two least square circle respectively derived from outlines in a circumferential direction respectively obtained at two positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface on the outer circumferential side, and centers B and C respectively derived from a respective one of two chamfered surfaces on the outer circumferential side in the substrate thickness direction, are located such that a sum of respective distances between A and B, and A and C, is 1 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular hole at a center, and includes a pair of main surfaces and a side wall surface orthogonal to the main surfaces. A roundness of the circular hole is 1.5 ?m or less. A difference between a maximum value and a minimum value of radii of three inscribed circles that are respectively derived from outlines in the circumferential direction at three positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface of the circular hole is 3.5 ?m or less.

Abstract: A magnetic-disk glass substrate capable of suppressing turbulence of air flow in a vicinity of an outer circumferential side edge portion of the magnetic disk and suppressing disk flutter is provided. This magnetic-disk glass substrate includes a pair of main surfaces, a side wall surface formed on an outer circumferential side edge surface, and chamfered surfaces interposed between the side wall surface and the main surfaces, respectively. The side wall surface has a roundness of 1.5 ?m or less. A difference in radius between an inscribed circle and a circumcircle of a plurality of outlines of the side wall surface at a plurality of positions that include a central position of the magnetic-disk glass substrate in a thickness direction and are different from each other in the thickness direction is 5 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular hole at a center, and includes a pair of main surfaces and a side wall surface orthogonal to the main surfaces. A roundness of the circular hole is 1.5 ?m or less. A difference between a maximum value and a minimum value of radii of three inscribed circles that are respectively derived from outlines in the circumferential direction at three positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface of the circular hole is 3.5 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular center hole a pair of main surfaces and an edge surface. The edge surface has a side wall surface and chamfered surfaces interposed between the side wall surface and the main surfaces, and a roundness of an edge surface on an outer circumferential side is 1.5 ?m or less. Also, a midpoint A between centers of two least square circle respectively derived from outlines in a circumferential direction respectively obtained at two positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface on the outer circumferential side, and centers B and C respectively derived from a respective one of two chamfered surfaces on the outer circumferential side in the substrate thickness direction, are located such that a sum of respective distances between A and B, and A and C, is 1 ?m or less.

Abstract: A magnetic-disk glass substrate capable of suppressing turbulence of air flow in a vicinity of an outer circumferential side edge portion of the magnetic disk and suppressing disk flutter is provided. This magnetic-disk glass substrate includes a pair of main surfaces, a side wall surface formed on an outer circumferential side edge surface, and chamfered surfaces interposed between the side wall surface and the main surfaces, respectively. The side wall surface has a roundness of 1.5 ?m or less. A difference in radius between an inscribed circle and a circumcircle of a plurality of outlines of the side wall surface at a plurality of positions that include a central position of the magnetic-disk glass substrate in a thickness direction and are different from each other in the thickness direction is 5 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular hole at a center, and includes a pair of main surfaces and a side wall surface orthogonal to the main surfaces. A roundness of the circular hole is 1.5 ?m or less. A difference between a maximum value and a minimum value of radii of three inscribed circles that are respectively derived from outlines in the circumferential direction at three positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface of the circular hole is 3.5 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular center hole, a pair of main surfaces and an edge surface. The edge surface has a side wall surface and chamfered surfaces interposed between the side wall surface and the main surfaces, and a roundness of an edge surface on an outer circumferential side is 1.5 ?m or less. Also, a midpoint A between centers of two least square circle respectively derived from outlines in a circumferential direction respectively obtained at two positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface on the outer circumferential side, and centers B and C respectively derived from a respective one of two chamfered surfaces on the outer circumferential side in the substrate thickness direction, are located such that a sum of respective distances between A and B, and A and C, is 1 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular center hole, a pair of main surfaces and an edge surface. The edge surface has a side wall surface and chamfered surfaces interposed between the side wall surface and the main surfaces, and a roundness of an edge surface on an outer circumferential side is 1.5 ?m or less. Also, a midpoint A between centers of two least square circle respectively derived from outlines in a circumferential direction respectively obtained at two positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface on the outer circumferential side, and centers B and C respectively derived from a respective one of two chamfered surfaces on the outer circumferential side in the substrate thickness direction, are located such that a sum of respective distances between A and B, and A and C, is 1 ?m or less.

Abstract: A magnetic-disk glass substrate has a circular hole at a center, and includes a pair of main surfaces and a side wall surface orthogonal to the main surfaces. A roundness of the circular hole is 1.5 ?m or less. A difference between a maximum value and a minimum value of radii of three inscribed circles that are respectively derived from outlines in the circumferential direction at three positions spaced apart by 200 ?m in a substrate thickness direction on the side wall surface of the circular hole is 3.5 ?m or less.

Abstract: A magnetic-disk glass substrate capable of suppressing turbulence of air flow in a vicinity of an outer circumferential side edge portion of the magnetic disk and suppressing disk flutter is provided. This magnetic-disk glass substrate includes a pair of main surfaces, a side wall surface formed on an outer circumferential side edge surface, and chamfered surfaces interposed between the side wall surface and the main surfaces, respectively. The side wall surface has a roundness of 1.5 ?m or less. A difference in radius between an inscribed circle and a circumcircle of a plurality of outlines of the side wall surface at a plurality of positions that include a central position of the magnetic-disk glass substrate in a thickness direction and are different from each other in the thickness direction is 5 ?m or less.

Abstract: A manufacturing method of a glass substrate for a magnetic disk is provided whereby nano pits and/or nano scratches cannot be easily produced in polishing a principal face of a glass substrate using a slurry containing zirconium oxide as an abrasive. The manufacturing method of a glass substrate for a magnetic disk includes, for instance, a polishing step of polishing a principal face of a glass substrate using a slurry containing, as an abrasive, zirconium oxide abrasive grains having monoclinic crystalline structures (M) and tetragonal crystalline structures (T).

Abstract: A manufacturing method of a glass substrate for a magnetic disk is provided whereby nano pits and/or nano scratches cannot be easily produced in polishing a principal face of a glass substrate using a slurry containing zirconium oxide as an abrasive. The manufacturing method of a glass substrate for a magnetic disk includes, for instance, a polishing step of polishing a principal face of a glass substrate using a slurry containing, as an abrasive, zirconium oxide abrasive grains having monoclinic crystalline structures (M) and tetragonal crystalline structures (T).

Abstract: A multilayered printed wiring board has a core substrate having a through hole opening with a radius R, a through hole structure formed at the through hole opening and including a lid-shaped conductive structure, a first interlaminar resin insulation layer formed over the core substrate and having a first via hole structure with a bottom radius r, and a second interlaminar resin insulation layer formed over the first interlaminar resin insulation layer and having a second via hole structure. The lid-shaped conductive structure is formed over the core substrate at an end portion of the through-hole opening and covering the end portion of the through-hole opening. The first via hole structure is formed on the lid-shaped conductive structure and has an electroless plated film and an electrolytic plated film. The second via hole structure has an electroless plated film and an electrolytic plated film.

Abstract: A printed wiring board including resin insulation layers, and conductive circuits formed between the resin insulation layers such that spaces between the conductive circuits are filled with a resin material of the resin insulation layers. The conductor circuits include a first conductive circuit and a second conductive circuit positioned adjacent to the first conductive circuit, each of the first and second conductive circuits has a trapezoidal cross section, and the first and the second conductive circuits satisfy a formula, 0.10T?|W1?W2|?0.73T where W1 represents a width of a space between upper surfaces of the first and second conductive circuits, W2 represents a width of a space between lower surfaces of the first and second conductive circuits, and T represents a thickness of each of the first and second conductive circuit.

Abstract: A printed wiring board including resin insulation layers, and conductive circuits formed between the resin insulation layers such that spaces between the conductive circuits are filled with a resin material of the resin insulation layers. The conductor circuits include a first conductive circuit and a second conductive circuit positioned adjacent to the first conductive circuit, each of the first and second conductive circuits has a trapezoidal cross section, and the first and the second conductive circuits satisfy a formula, 0.10T?|W1?W2|?0.73T where W1 represents a width of a space between upper surfaces of the first and second conductive circuits, W2 represents a width of a space between lower surfaces of the first and second conductive circuits, and T represents a thickness of each of the first and second conductive circuit.

Abstract: A printed wiring board having an interlayer insulation layer and conductive circuits formed on the interlayer insulation layer. The conductive circuits include a first conductive circuit and a second conductive circuit positioned adjacent to each other, and the first and second conductive circuits satisfy a formula, 0.10 T?|W1?W2|?0.73 T, where W1 represents an upper conductive circuit space between the first and second conductive circuits, W2 represents a lower conductive circuit space between the first and second conductive circuits, and T represents a thickness of the first and second conductive circuits.

Abstract: A semiconductor mounting board 80 is prepared by electrically joining an IC chip 70 via an interposer 60 of high rigidity to external pads 41 and internal pads 43, which are formed on the uppermost surface of a build-up layer 30. When the IC chip 70 generates heat, since pads 41 are positioned away from the center, a large shearing stress is applied to the portions at which pads 41 are joined to the interposer 60 in comparison to the portions at which pads 43 are joined to the interposer 60. Here, pads 41 are formed at substantially flat wiring portions and thus when joined to the interposer 60 by means of solder bumps 51, voids and angled portions, at which stress tends to concentrate, are not formed in the interiors of solder bumps 51. The joining reliability is thus high.

Abstract: A multilayered printed wiring board has a core substrate having a through hole opening with a radius R, a through hole structure formed at the through hole opening and including a lid-shaped conductive structure, a first interlaminar resin insulation layer formed over the core substrate and having a first via hole structure with a bottom radius r, and a second interlaminar resin insulation layer formed over the first interlaminar resin insulation layer and having a second via hole structure. The lid-shaped conductive structure is formed over the core substrate at an end portion of the through-hole opening and covering the end portion of the through-hole opening. The first via hole structure is formed on the lid-shaped conductive structure and has an electroless plated film and an electrolytic plated film. The second via hole structure has an electroless plated film and an electrolytic plated film.