Hitachi, Ltd.

Naoya Kitamura

Takashi Inoue

Hitoshi Yokono

Hideo Arima

Hideyasu Murooka

Masayuki Kyooi

Hitoshi Oka

Fusaji Shoji

Yutaka Akiba

Yasunori Narizuka

Fumio Kataoka

Haruhiko Matsuyama

Hirayoshi Tanei

Yoshihide Yamaguchi

Hidetaka Shigi

Tetsuya Yamazaki

Masashi Nishiki

Yukio Maeda

Takehiko Hasebe

Hisashi Sugiyama

Makio Watanabe

Ryoji Iwamura

Masayuki Kyoui

A low-EMI circuit which realizes a high mounting density by converting the potential fluctuation of a power supply layer with respect to a ground layer which occurs on switching an IC device etc., into Joule's heat in the substrate without using any parts as a countermeasure against the EMI. Its structure, a circuit board using it, and a method of manufacturing the circuit board are also disclosed. Parallel plate lines in which the Q-value of the stray capacitance between solid layers viewed from the power supply layer and ground layer is equivalently reduced and which are matchedly terminated by forming a structure in which a resistor (resistor layer) and another ground layer are provided in addition to the power supply layer and the ground layer on a multilayered circuit board. A closed shield structure is also disclosed.

Low-EMI electronic apparatus, low-EMI circuit board, and method of manufacturing the low-EMI circuit board

A multi-layer wiring substrate capable of high density packaging, and a method of manufacturing the same, in which a carrier substrate, in which through holes can be easily formed in high density corresponding substantially to a pitch of connecting terminals in a semiconductor chip, and build-up layers are formed on the substrate with the application of a conventional build-up technique. When the build-up technique for repeatedly forming insulating layers and wiring layers on a carrier substrate is used to manufacture a multi-layer wiring substrate, the carrier substrate is formed in the following manner. First, an insulating resin layer is formed in a copper foil, in which a plurality of first windows are regularly provided, to cover the copper foil, and the resin layer fills the interior of the windows. Subsequently, second windows of a particular shape are provided in regions of layers of the insulating resin filled in the windows, and independent conducting paths are formed through the second windows to extend from front sides of the second windows to back sides thereof. The conducting paths are formed radially to be spaced a substantially equal distance from centers of the respective second windows.

Multi-layer wiring substrate and manufacturing method thereof

A low-EMI circuit which realizes a high mounting density by converting the potential fluctuation off a power supply layer with respect to a ground layer which occurs on switching an IC device etc., into Joule's heat in the substrate without using any parts as a countermeasure against the EMI. Its structure, a circuit board using it, and a method of manufacturing the circuit board are also disclosed. Parallel plate lines in which the Q-value of the stray capacitance between solid layers viewed from the power supply layer and ground layer is equivalently reduced and which are matchedly terminated by forming a structure in which a resistor (resistor layer) and another ground layer are provided in addition to the power supply layer and the ground layer on a multilayered circuit board. A closed shield structure is also disclosed. This invention can remarkably suppress unwanted radiation by absorbing the potential fluctuation (resonance) which occurs in a power supply loop by equivalently reducing the Q-value of the stray capacitance, absorbing the standing wave by the parallel plate lines matchedly terminated and, closing and shielding the parallel plate lines.

Low-EMI electronic apparatus, low-EMI circuit board, and method of manufacturing the low-EMI circuit board.

A multilayer wiring board fabricating method and a multilayer wiring board fabricated with use of the method that a solvent-free fluid polymer precursor is put on a wiring layer of a base substrate, and space among the wirings is exhausted and is filled with the precursor, and the precursor is hardened under a hydrostatic pressure and then the next wiring layer is formed before the above process is repeated one or more times. The multilayer wiring board fabricating method is excellent in the mass productivity and low cost and in that the wiring can be made highly dense with the substrate having vertical via conductors for connection among the conductor layers.

Multilayer wiring board fabricating method

A thin film multilayer wiring board-producing method of the present invention is intended to decrease thermal stresses developing during the formation of the multilayer construction, and also to greatly reduce the number of the steps of the process, as compared with a conventional method. A film material can be used as an insulating film of the multilayer wiring board, and is adhesively bonded to a predetermined portion. Wiring conductors are formed by electroplating. The wiring layers are repeated laminated to form the multilayer construction. A metallic film serving as an electrode is formed on one of upper and lower surfaces of a substrate, the metallic film being removed after a multilayer wiring is formed. A soluble insulating film is formed on a metallic undercoat film on the substrate, and grooves are formed in the soluble insulating film, and wiring conductors are formed in the grooves, using either electroplating or both electroplating and electroless plating. Thereafter, the soluble insulating film and the metallic undercoat film are removed. Subsequently, an insoluble insulating film is formed at those locations from which the soluble insulating film and the metallic undercoat have been removed.

Method of producing a thin film multilayer wiring board

A process for the fabrication of an interconnected multilayer board involves the steps of forming a metallic under-conductive layer on a base substrate, forming a windowed resist layer on the metallic under-conductive layer, filling windows of the resist layer with a conductor by plating thereby forming a conductor layer, forming another windowed resist layer on the conductor layer and filling windows of this resist layer with a conductor by plating, thereby forming a via-hole layer and to provide a two-level structure of the conductor layer and the via-hole layer. Thereafter, the resist layers and portions of the metallic under-conductor layer other than those in contact with a lower face of the conductor constituting the conductor layer are dissolved to form a two-level skeleton structure of conductor lines and spaces within the skeleton structure are filled with a varnish in a solventless form and the varnish is cured.

Process for fabricating an interconnected multilayer board

Described herein are interconnected mutilayer boards and their fabrication processes. Multilayer conductor lines of a skeleton structure are formed by conducting multilayer metallization while including all resist layers and metallic under-conductive layers and then removing the resist layers and metallic under-conductive layers at once. Spaces between the multilayer conductor lines of the skeleton structure are then filled with a solventless varnish so that insulating layers are formed. Modules making use of such interconnected multilayer boards and computers having such modules are also described.

Interconnected multilayer boards and fabrication processes thereof

Growing community of inventors

Yokohama, Japan

Naoya Kitamura