Abstract:
A flexible circuit board device for connecting to an electronic device comprised of a flexible circuit board made from flexible resistive film, an adhesive layer formed on the flexible resistive film, electrical conductive circuits formed on the adhesive layer and cured films filling the gaps between the conductive circuits. The electrical conductive circuits are formed of conductor metal foil and a plating film covering the surface of the conductor.
Abstract:
To make a printed circuit board, bores bridge gaps between where conductor paths are to be located, and are then filled with an adhesive. The gaps between where the conductor paths are to be located then caustically removed so that a conductor path skeleton results which is held together by the adhesive bridges. Finally, the conductor path skeleton is affixed to an insulating layer.
Abstract:
After pads 2 for mounting parts are formed at desired positions on an insulating board 1 in a circuit forming process using etching resist 3, the etching resist 3 is left on the pads without peeling it off. A first photosolder resist 4 is then formed between the pads 2, exposed to light, and developing using a solvent able to separate the etching resist 3 as a developing liquid, following which the etching resist 3 is peeled off together with the not yet fully hardened first photosolder resist 4. After formation of the first photosolder resist 4, a second photosolder resist is formed on desired areas excluding the interspaces between the pads 2, exposed to light, and developed. Consequently, when a photosolder resist is formed between pads pitched at narrow intervals on a printed wiring board, attachment of the photosolder resist to the pads due to misalignment between the insulating board and a photo-mask can be avoided.
Abstract:
A fabrication method of a printed wiring board in which the halation effect of light irradiated to a solder resist film is utilized in a process of selectively removing the solder resist film. After a conductive layer is patterned to a given circuit pattern including soldering pads, the solder resist film is formed on the base material to cover the patterned conductive layer. The solder resist film is selectively exposed to light utilizing reflection of the irradiated light from the insulating base material and developed so that the solder resist film is selectively left in areas adjacent to the respective soldering pads. Then, an etching resist film is formed to cover the patterned conductive layer except for the soldering pads, and surface areas of the respective soldering pads are selectively etched using the etching resist film as a mask to produce solder resist dams made of the solder resist film left on the base material. Solder films are formed on the respective soldering pads thus selectively etched. Electronic components can be soldered on the soldering pads with satisfactory reliability even if the soldering pads have narrow pitches such as 500 .mu.m or less.
Abstract:
A circuit board includes a circuit-conductor layer, a ground layer and a power source layer superposed in a multilayer form through dielectric layers therebetween, A heat conduction through inside of the circuit board is enhanced so that circuit chips mounted on the circuit board can be cooled down to a level capable of operating normally, The circuit board can be formed to be compact, In order to enhance the heat transfer in the circuit board, at least one of the ground layer and power source layer is formed in a multilayer manner, It is preferable to form these layers at a thickness larger than that of the circuit-conductor layer, Further, preferably, the pin of the chip mounted on the board and at least one of the ground layer and power supply layer are connected to each other in such a manner as to enhance the heat conduction.
Abstract:
This invention provides a method of forming a circuit wiring pattern which cannot be formed by a prior art method such as etching or plating. This method comprises a step of forming trenches for forming a circuit wiring pattern at predetermined positions on at least one of the surface of an insulating base material and then filling a conductive material into the trenches, a step of removing conductor layers in such a manner that the conductor layers formed by the step described above exist only in the trenches formed in the insulating base material and gap portions of the circuit wiring pattern comprising the conductor layers formed in the trenches of the insulating base material are exposed, and a step of forming an insulating surface protection layer.
Abstract:
Patterned electrically conductive structures, such as circuit elements, in single or multiple laminar form, and their manufacture. The basic laminar structure is made by sizing a removable substrate to substantially equal depth with an electrically conductive material over a given area configured as a circuit element and with an electrically non-conductive material elsewhere, bonding the respective sizing materials in place and together, and separating the substrate to leave a lamina of electrically conductive and non-conductive materials side-by-side. Face-to-face juxtaposition of such substrate-less laminae provides built-up or laminated products.
Abstract:
A multilayer printed wiring board is described having (1) an inner layer conductive pattern on an organic insulating base material, (2) a poly(vinyl acetal)-phenolic resin coating containing an amine substituted organic zirconate or titanate coupling agent, (3) a dielectric insulating layer, (4) a bonding composition capable of being adhesion promoted for electroless metal deposition comprising a phenolic resin having at least two methylol groups and substantially free of methyl ether groups, a heat resistant aromatic or cyclic resin having functional groups capable of reacting with the methylol groups without the evolution of water, and (5) an outer conductive pattern, the multilayer board being capable of withstanding at least five soldering cycles of at least 255.degree. C. for 2 seconds without blistering or delamination. Processes for manufacturing the multilayer board are also described.
Abstract:
A printed resistor comprising an insulating matrix board, copper layers printed on one side of said board by etching and having predetermined patterns, impedance layers screen-printed on the other side of said board, and conductors applied in holes formed in said board and extending through said holes for electrically connecting between selected ones of said copper layers and said impedance layers.