Abstract:
A method 10, 110 for making multi-layer circuit boards having metallized apertures 38, 40, 130, 132 which may be selectively and electrically grounded and having at least one formed air-bridge 92, 178.
Abstract:
A bus wiring plate body (20), for an electric coupling box, is arranged in a manner that bus bar members (23, 24) are wired between pre-hardening epoxy resin plates (21, 22) and these pre-hardening epoxy resin plates are subjected to a heat pressing process to thereby integrate the pre-hardening epoxy resin plates (21, 22) and the bus bar members (23, 24) in a laminated state. When hardened epoxy resin plates (25, 26) are disposed outside of the pre- hardening epoxy resin plates (21, 22), respectively, the strength of the bus bar wiring plate body (20) can be improved. Thus, since the bus bar members (23, 24) are sealed in an insulated state, leak current is reduced. Further, the thickness of the bus bar wiring plate body (20) is reduced to a large extent, so that the electric coupling box can be miniaturized and lightweighted.
Abstract:
To reduce warping of a copper clad laminate coated with copper foils of different thicknesses on both sides, and thereby to improve production efficiency of the printed-wiring boards, there is provided a copper clad laminate coated with copper foils of different thicknesses on both sides, wherein a first copper foil on one side of the laminate is not recrystallizable by hot pressing for production of said laminate and a second foil on the other side is recrystallizable by the hot pressing and thicker than the first foil.
Abstract:
A producing method of a multilayer circuit board for ensuring that a circuit board, such as an interposer, is provided on the multilayer circuit board. The method includes the steps of forming the interposer on a support board; forming a multilayer circuit board separately from the interposer; joining the interposer formed on the support board to the multilayer circuit board; and then removing the support board. According to this method, even if the production of the interposer fails after the production of the multilayer circuit board, it is possible to scrape the interposer only and there is no need to scrap it together with the multilayer circuit board. Besides, although the interposer is so thin and limp, since it is formed on the support board, the interposer can surely and readily be joined to the multilayer circuit board.
Abstract:
The present invention relates generally to new planar substrates that are metallized and embedded with material to minimize the camber and method thereof. The invention also relates to the fabrication of multilayer ceramic (MLC) substrates for packaging electronic devices. More particularly, this invention relates to the fabrication of thin and small ceramic substrates which do not need post-sintering processing to control the flatness of the sintered product.
Abstract:
A ceramic circuit substrate includes an insulating layer fabricated of a ceramic, a first surface conductor layer fabricated on a surface of the insulating layer and embedded in the insulating layer except at least its surface, and a second surface conductor layer fabricated to be stacked on the first surface conductor layer. A method of fabricating the ceramic circuit substrate includes the steps of printing a first surface conductor layer on a surface of a ceramic green sheet forming an insulating layer, laminating the green sheet and another green sheet on which an inner conductor layer is printed, and co-firing the green sheets, thereby fabricating the first surface conductor layer on a surface of a multilayer substrate, and printing a second surface conductor layer on the first surface conductor layer so that the second surface conductor layer is stacked on the first surface conductor layer and firing the second surface conductor layer, thereby fabricating the two stacked surface conductor layers on the surface of the multilayer substrate.
Abstract:
An electronic control board assembly has a large-current control unit and a small-current control unit connected to the large-current control unit. The large-current control unit has an insert-molded board with lead frames embedded therein. The insert-molded board has a first component mounting surface and a first component soldering surface facing away therefrom. A first group of components are mounted on the first component mounting surface and have leads extending through the insert-molded board and soldered to the lead frames. The small-current control unit has a printed wiring board which has a second component mounting surface and a second component soldering surface facing away therefrom. A second group of components are mounted on the second component mounting surface and have leads extending through the printed wiring board and soldered to interconnections patterned on the second component soldering surface. The lead frames have ends extending through the printed wiring board and soldered to the interconnections. The first component soldering surface and the second component soldering surface face outwardly.
Abstract:
A power/ground structure and associated circuit card or board are provided in which the coefficient of thermal expansion of the power/ground structure and associated circuit board are closely matched to each other. The circuit board or card is formed of organic electrically-insulating material having electrical circuitry thereon which carries an integrated circuit chip. The power/ground assembly is formed of alternating layers of organic insulating material and at least two layers of electrically-conducting material, typically copper, one of the layers of electrically-conducting material forming a power connection and another layer of the electrically-conducting material forming a ground plane. There is also at least one additional layer of a structural material having a relatively high Young's Modulus and a CTE of less than about 10 PPM/.degree.C. Invar or copper clad Invar are preferred materials for this structure. The electrically-conducting copper material and the Invar are selected in thickness and number such that, together with the electrically-insulating material, the composite CTE of the power/ground structure closely matches that of the circuit card or board.
Abstract:
A printed circuit board that is formed as a shaped part of plastic. Interconnects formed of punched leadframes are embedded into this printed circuit board in one or more planes. Moreover, flat plugs are integrally formed by the leadframes. Components, particularly relays, are preferably welded to bent-off tabs of the leadframes.
Abstract:
This invention concerns a hybrid printed circuit board which permits easy and reliable connection between small-current circuit conductors and large-current circuit conductors. The hybrid printed circuit board of this invention comprises: an insulating substrate of synthetic resin having fixing bosses erected thereon; a flexible printed circuit sheet having small-current circuit conductors; and busbars as large-current circuit conductors; wherein the flexible printed circuit sheet is stacked and arranged on the insulating substrate so that the fixing bosses erected on the insulating substrate pass through and above the flexible printed circuit sheet, the busbars as large-current circuit conductors are put in contact with the small-current circuit conductors, and the fixing bosses are heated and deformed to fix the busbars in place.