Hitachi, Ltd.

Hitachi Techno Engineering Co., Ltd.

Hideyasu Murooka

Masayuki Kyooi

Naoya Kitamura

Osamu Yamada

Takashi Inoue

Hitoshi Yokono

Hitoshi Oka

Fusaji Shoji

Fumio Kataoka

Hideo Arima

Haruhiko Matsuyama

Akimi Miyashita

Yoshihide Yamaguchi

Hisashi Sugiyama

Mutsumasa Fujii

Kiyonori Kogawa

Makio Watanabe

Ryoji Iwamura

Masami Kawaguchi

Masayuki Kyoui

Noriaki Ujiie

Nobuaki Ooki

Keiichiro Torii

Minoru Kubosawa

Kaoru Ono

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 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

A hot press including a displaceable sleeve for surrounding materials of a multi-layer substrate under a reduced pressure condition, a gas pressurizing condition and a heating condition with thermal plates. Upper and lower sealing units seal an interior of the sleeve, with a mechanism lowering and raising the sleeve. A pilot check mechanism prevents a lower bolster from raising/lowering upon the reduced pressure condition and the gas pressure condition, and a retainer maintains the lowered or raised condition of the sleeve. The multi-layer substrate is formed under the reduced pressure condition and the gas pressure condition. Accordingly, the atmosphere and moisture between the materials of the multi-layer substrate and volatile composition are removed. Additionally, a void generated during the heat and pressure process by the heating plates is eliminated from the multi-layer substrate. By carrying out the formation of the multi-layer substrate at the heat and pressure by the heating plates under the gas pressure condition, a final dimensional precision and shape are enhanced and a warpage or twist is suppressed.

Hot press

A method and an apparatus of forming a multilayer printed circuit board which can positively remove voids in the prepregs in the printed board and enhance the reliability of the produced printed circuit board and is superior in economy, wherein a laminated assembly of a plurality of printed circuit board components and a plurality of prepregs alternately laminated on each other is sandwiched between upper and lower jig plates, and the laminated assembly sandwiched between the jig plates is clamped between heating plates of a bonding press to heat the assembly to a predetermined temperature, and, thereafter, a pressure is applied to the upper and lower jig plates so as to urge them against each other for bonding the printed circuit board component and the prepregs. An exterior pressurizing means is provided around the printed circuit board components and the prepregs sandwiched between the upper and lower jig plates in order to prevent the molten prepregs from flowing outwardly, thereby raising the fluid pressure of the molten prepregs to squeeze out air bubbles existing in the prepregs.

Method of forming a multilayer printed circuit board and apparatus

A hot press capable of minimizing a displacement of one substrate from another in multilayer printed circuit boards each constituted by a plurality of substrates having wiring pattern groups printed thereon which are pressed together by applying pressure into a multilayer printed circuit board. The end is attained by minimizing a variation in thickness from a central portion of the board to a peripheral portion thereof. The hot press includes plate thickness adjusting devices each interposed between each bolster and each heat insulating member to compress and deform the heat insulating members beforehand. By imparting a deformation beforehand to each heat insulating member, contacting surfaces of the heat insulating members become substantially planer when they are compressed as pressure is applied to the substrates to press them together into a multilayer printed circuit board, thereby minimizing the variation in thickness from one portion to another in the multilayer printed circuit board produced by the hot press.

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Yokohama, Japan

Hideyasu Murooka