Fujitsu Corporation

Mikio Nishihara

Kiyoshi Kuwabara

Kyoichiro Kawano

Akira Tamura

Kiyokazu Moriizumi

Hidehisa Sakai

Masahiro Oda

Kiyotaka Seyama

Teruo Murase

Kazuhisa Tsunoi

Takamitsu Tsuchimoto

Masaru Matsumoto

Osamu Ohshima

To provide electrical conduction between front and back surfaces of a thin film multi-layered circuit board, such as an MCM, at low cost without using a simultaneous firing process for ceramic. The thin film multi-layered circuit board has at least one thin film circuit layer on a first surface of a substrate, wherein a conductor layer is disposed in the lowermost layer of the thin film circuit layer in contact with the first surface of the substrate, and is characterized in that holes for providing the electrical conduction between front and back surfaces of the substrate are formed through the substrate from the first surface to a second surface thereof so that the conductor layer is exposed in the hole, wherein the diameter of the hole is gradually enlarged from the first surface to the second surface.

High density thin film circuit board and method of production thereof

In a circuit arrangement for a multilayer printed circuit board, a first circuit layer is formed on a substrate, and comprises a dielectric layer having a circuit pattern formed thereon. A second circuit layer is further formed on the first circuit layer, and comprises a dielectric layer having a circuit pattern formed thereon. The first circuit pattern includes conductive segments having only an X-directional component, and the second circuit pattern includes conductive segments having only an Y-directional component perpendicular to the X-directional component. Electric connections between the X-directional segments and the Y-directional segments are suitably established by vias provided in the second layer. The first circuit pattern further includes slant conductive segments having both the X- and Y-directional components and arranged in a blank zone not occupied by the X-directional segments, and the second circuit pattern further includes slant conductive segments having both the X- and Y-directional components and arranged in a blank zone not occupied by the Y-directional segments. Electric connections between the slant segments of the first pattern and the slant segments of the second pattern are suitably established by vias provided in the second layer.

Circuit arrangement for multilayer printed circuit board

A contact pin includes: a pin terminal secured to a stationary base art by press-fitting a press-fitted part into the stationary base part, the pin terminal projecting from the stationary base part and being joined to the board; a contact part inserted into a contact pin through-hole of a movable lock part so that a plug pin terminal is fitted into the contact part; and an auxiliary plate 6 reinforcing the press-fitted part, engaged with the movable lock part and transmitting a force caused by a movement of the movable lock part to the press-fitted part. A connector constructed in the described manner includes a plurality of above-mentioned contact pins.

Method of assembling a connector using frangible contact parts

Connector and method of assembling the same

A method of making an engineering change to a printed wiring board changes connection for a terminal of an electronic component which is mounted on the printed wiring board through a terminal pad. The terminal is electrically connected to a destination through the terminal pad and wiring within the printed wiring board. The present invention places an insulator, including an insulating material and a conductive layer formed thereon, between the terminal and the terminal pad. The electronic component is mounted on the printed wiring board and the terminal is electrically connected to the conductive layer. A discrete wire is placed between the conductive layer and the destination.

Method of making an engineering change to a printed wiring board

A wiring structure for a termination circuit in which a termination circuit is connected to an integrated circuit through a fixed wiring pattern provided in a leadout layer closest to the mounting surface.

Wiring structure of termination circuit

A multilayer printed wiring board having an air gap between neighboring printed wiring boards of the multilayer printed wiring board by inserting plated spacers to both end faces of through-hole pads which are provided to each printed wiring board so that each through-hole pad opposes to another through-hole pad on the neighboring printed wiring board. The spacers opposed to each other are joined together by solder, and each spacer has an end surface having a size being smaller than a size of the end surface of each through-hole pad to provide a drop part at the joint part of the spacers, so that melted solder stays at the drop part not flowing toward the board through the side surface of the through-hole pad when the printed wiring boards are integrated to the multilayer printed wiring board under pressure and high temperature.

Multilayer printed wiring board

A high density multilayer printed circuit board comprising generally parallel signal layers, electric source layers, and ground layers, with insulating layers arranged between the signal layers and the electric source layers, between the electric source layers and the ground layers, and between the ground layers and the signal layers respectively. Conductor portions are formed in through holes which are opened in a direction transverse to the signal layers, electric source layers, and ground layers. The conductor portions are electrically connected to the signal layers and/or the electric source layers, and/or the ground layers, through the lands thereof, the connections of the lands being substantially equally distributed among the conductor portions.

High density multilayer printed circuit board

A printed board comprising a plurality of through holes formed therein and located on intersecting points of an X-Y orthogonal basic grid, and an oblique conductor pattern, wherein conductors are formed along channels arranged in accordance with a principle that one conductor passes between adjacent grid points arranged in the X direction, while two or more conductors pass between adjacent grid points arranged in the Y direction, and each conductor obliquely extends in a zigzag line without contacting the grid points. Such conductor pattern ensures a high density and minimum length of wiring.

Printed board

This application discloses a multilayer printed wiring board having a plurality of pattern layers. Said printed wiring board has at least one pair of plated through holes, i.e. a first and a second plated through hole. The first plated through hole is directly connected to said patterns. The second plated through hole is not directly connected to said patterns. An electronic element terminal is connected to said second plated through hole. The first and second plated through holes are electrically connected to each other on a surface opposite an element mounting surface of the printed wiring board.

A multi-layer printed circuit board has a through hole extending therein outside the mounting portion of a component mounted on the surface layer of the board. The component has a lead pad on the surface layer of a first printed circuit board and a modification pad on the surface layer between the through hole and the lead pad. The through hole extends through the first board to inside the mounting portion via a pattern of an internal wiring layer of the board. A second printed circuit board is joined to the first board at the internal layers of each to form a unitary integrated circuit board. Another through hole extends through the first and second boards inside the mounting portion of the integrated printed circuit board. The pattern and a selected wiring layer of the second board are thereby connected via the other through hole. Additional through holes extend through the second board and interconnect the layers of the second board. The additional through holes are positioned in areas devoid of the first-mentioned through hole.

Growing community of inventors

Kawasaki, Japan

Mikio Nishihara