Fujitsu Corporation

Kenji Iida

Takashi Nakagawa

Tomoyuki Abe

Yasutomo Maehara

Hideaki Yoshimura

Shin Hirano

Norikazu Ozaki

Seigo Yamawaki

Kenichiro Abe

Yasuhito Takahashi

Yuichiro Ohta

Hiroyuki Katayama

Toshiro Katsube

Masaru Sumi

Yasunaga Kurokawa

Kazuo Nakano

Kenji Fukuzono

Takashi Kanda

Kazuaki Satoh

Koji Komemura

Takashi Shuto

Kenji Takano

Junichi Kanai

Yasuhiro Karahashi

Hitoshi Suzuki

Nobuyuki Hayashi

Motoaki Tani

Kiyotaka Seyama

Hiroaki Date

Kazumasa Saito

Tomohisa Yagi

Keiji Arai

Kaoru Sugimoto

Seiichi Sugano

Takefumi Kashiwa

A method for producing circuit board, including: adhering plastic deformable insulating material onto surface of laminate, which contains second-metal-layer of second metal, and first-metal-layer in pattern on second-metal-layer, and the surface of the laminate is surface of second-metal-layer where first-metal-layer is formed, and surface of first-metal-layer, followed by curing the material, and removing second-metal-layer to form plate structure to which first-metal-layer in pattern is formed; opening hole in cured material from surface of the plate structure opposite to surface thereof where first-metal-layer is formed, until the hole reaches first-metal-layer; filling the hole with electroconductive paste, to form the plate structure filled therewith; and laminating one plate structure filled therewith with the other plate structure filled therewith in manner that first-metal-layer of one plate structure filled therewith faces opening of the hole of other plate structure filled therewith, wherein first-metal-layer contains metal different from second metal.

Circuit board, production method of circuit board, and electronic equipment

Production method of circuit board

A printed circuit board includes a cell portion which includes cells having a plurality of through bores are arranged in a base material; and a base material portion which exists around an outer edge of the cell portion. The base material is formed of a prepreg, the prepreg includes a fiber material in which fiber threads are oriented in a first direction and in a second direction which is perpendicular to the first direction, and a resin material in which the fiber material is impregnated. The through bores are arranged along a third direction between the first direction and the second direction, wherein one side of the outer edges of the cell extends along the third direction.

Printed circuit board incorporating fibers

The method of producing a substrate comprises the steps of: forming a through-hole in a base member; filling the through-hole with an insulating material; performing electroless plating to coat the surface of the base member, in which the through-hole has been filled with the insulating material, with an electroless-plated layer; applying photo resist on the electroless-plated layer formed on the surface of the base member; optically exposing and developing the photo resist so as to form a resist pattern coating an end face of the through-hole filled with the insulating material; etching an electrically conductive layer formed on the surface of the base member with using the resist pattern as a mask; and removing the resist pattern coating the end face of the through-hole from the base member with using the electroless-plated layer as a release layer.

Method of producing substrate

A wiring substrate includes a core substrate having a first main surface and a mutually opposing second main surface, the second main surface having a conductive property. A first through hole penetrates a core substrate. A first conductive layer extends from the first main surface to the second main surface via the first through hole. An insulating layer is formed on the first conductive layer. A second through hole has the insulating layer as an interior wall. And a second conductive layer is formed inside the second through hole.

Wiring substrate including conductive core substrate, and manufacturing method thereof

The circuit board is capable of tightly bonding a cable layer on a base member even if thermal expansion coefficients of the base member and the cable layer are significantly different. The circuit board comprises: the base member; and the cable layer being laminated on the base member with anchor patterns, which are electrically conductive layers formed on a surface of the base member.

Circuit board and method of producing the same

The method of producing a substrate comprises the steps of: forming a through-hole in a base member; plating the base member so as to coat an inner face of the through-hole with a plated layer; applying photo resist on the base member; optically exposing and developing the photo resist so as to form a resist pattern, which coats at least a planar area of the through-hole; and etching an electrically conductive layer formed on the surface of the base member. The resist pattern is formed so as to separate an area of exposing the conductive layer a prescribed distance away from an edge of the through-hole, and the prescribed length is longer than a distance of etching a side face of the conductive layer in the etching step.

A circuit board has a low thermal expansion coefficient that suits the thermal expansion coefficient of an element to be mounted thereupon and can prevent the occurrence of delamination and cracking of a core layer when the circuit board is used in a low temperature environment. The circuit board is constructed by laminating a core layer and at least one wiring layer, where the at least one wiring layer has slightly smaller external dimensions in a planar direction than the core layer.

Circuit board

The core layer of a core substrate is made of carbon fibers impregnated with resin. When the temperature of the core layer increases, the core layer suffers from an increase in the thickness because of thermal expansion of the resin. The core layer is sandwiched between the insulating layers containing glass fibers. The insulating layers serve to suppress an increase in the thickness of the core layer resulting from the thermal expansion of the core layer. Thermal stress is suppressed in the core substrate.

Core substrate and printed wiring board

Large-sized through holes are formed in a core layer of a printed wiring board. Large-sized vias are formed in the shape of a cylinder along the inward wall surfaces of the large-sized through holes located within a specific area. A filling material fills the inner space of the large-sized via. A small-sized through hole penetrates through the corresponding filling material along the longitudinal axis of the small-sized through hole. A small-sized via is formed in the shape of a cylinder along the inward wall surface of the small-sized through hole. The filling material and the core layer are uniformly distributed within the specific area in the in-plane direction of the core substrate. This results in suppression of uneven distribution of thermal stress in the core layer in the in-plane direction of the core layer.

Printed wiring board

The core substrate is capable of securely preventing short circuit between an electrically conductive core section and a plated through-hole section. The core substrate comprises: an electrically conductive core section having a pilot hole, through which a plated through-hole section is formed; electrically conductive layers coating the inner face of the pilot hole and a surface of the core section; a gas purging hole being formed in the conductive layer coating the surface of the core section; an insulating material filling a space between the inner face of the pilot hole and an outer circumferential face of the plated through-hole section; and cable layers being laminated on both side faces of the core section.

Core substrate and method of producing the same

A process for producing a multilayer board includes the steps of applying a bonding ink to the terminal of the first substrate, the bonding ink including a thermosetting resin containing a filler and a curing agent, the filler being formed of metal particles plated with solder, the metal particles each having a first melting point, and the solder having a second melting point lower than the first melting point; bonding the second substrate to a bonding sheet composed of a thermosetting resin and having a through hole disposed in a portion corresponding to the terminal of the second substrate; and heating and pressurizing the first and second substrates with the bonding sheet in such a manner that the terminals are opposite each other to effect curing of the bonding sheet and the bonding ink and to form an integral structure.

Process for producing multilayer board

The present invention relates to a method of manufacturing a wiring board comprising: a build-up layer, in which wiring patterns are piled with insulating layers; and a core substrate, which is separately formed from the build-up layer, the method comprising the steps of: separably forming the build-up layer on a plate-shaped support; electrically connecting the core substrate to the wiring patterns of the build-up layer on the support; and removing the support from the build-up layer so as to form the wiring board, in which the build-up layer is connected to the core substrate. By separably forming the build-up layer and the core substrate, the wiring board effectively exhibiting characteristics thereof can be produced.

Wiring board manufacturing method

A printed wiring board is made of first and second substrates superimposed on each other. The first and second substrates respectively include a core layer made of resin containing carbon fibers. The second substrate has the outline different from that of the first substrate. A stepped surface is defined on the front surface at least of the first substrate. Electrodes can be formed on the stepped surface as well as on the back surface of the first substrate and the front surface of the second substrate. This structure enables detection of an electric signal from the stepped surface. A further flexibility can thus be achieved in locating electrodes as compared with a conventional printed wiring board having uniform substrates simply superimposed on each other. This results in an expanded use or purpose for a printed wiring board.

The method of manufacturing a circuit board is capable of preventing deformation of a core substrate, ensuring size thereof and highly concentrating cable patterns so as to realize compact and high-performance semiconductor devices. The method of manufacturing a circuit board of the present invention comprises the steps of: forming a multilayered body, in which cable patterns on different layers insulated by an insulating layer are electrically connected, on a core substrate by a buildup process; and separating the multilayered body from the core substrate. A metal layer is vacuum-adhered on the core substrate. The multilayered body is formed on the metal layer by the buildup process and separated from the core substrate together with the metal layer by breaking the vacuum state between the core substrate and the metal layer

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Kawasaki, Japan

Kenji Iida