Abstract:
First, there are prepared a semiconductor chip with a group of solder bumps disposed on and joined to a surface thereof in a predetermined pattern, and a multilayer plate including a second layer as an electrically conductive layer and first and third layers disposed on respective opposite surfaces of the second layer and comprising metal layers of one metal. Then, the first layer and the third layer of the multilayer plate are etched in a predetermined pattern to form a first group of posts and a second group of posts which have a pattern identical to the pattern of the group of solder bumps. Then, semiconductor chip is positioned to hold the solder bumps in contact with the posts of the first group, and the solder bumps are melted to join the solder bumps to the posts of the first group. Thereafter, the second layer is cut between the posts of the first and second groups, producing separate multilayer posts.
Abstract:
An electrical structure, comprising a first dielectric layer, a patterned layer on the first dielectric layer, and a second dielectric layer on the patterned layer. The patterned layer includes a metal pattern on the first dielectric layer, a metallic pattern on the metal pattern, and a plugged pattern within a remaining space of the patterned layer. The plugged pattern includes a dielectric material. The second dielectric layer is adhesively bonded to a top surface of the patterned layer. The second dielectric layer includes the dielectric material.
Abstract:
There is disclosed herein a multilayer circuit board having air bridge crossover structures and a subtractive method for producing the same, wherein the circuit includes specially designed metallic fortifying layers which provide mechanical and/or electrical fortification to the circuit.
Abstract:
The present invention provides a novel method of etching nickle/iron alloy which employs a novel etchant. The novel etchant, which etches nickle/iron alloy but not copper, comprises an aqueous solution of ferric ammonium sulfate, and an acid selected from the group consisting of: sulfuric acid; phosphoric acid; and mixtures thereof.
Abstract:
The present invention provides a novel method of etching nickle/iron alloy which employs a novel etchant. The novel etchant, which etches nickle/iron alloy but not copper, comprises an aqueous solution of ferric ammonium sulfate, and an acid selected from the group consisting of: sulfuric acid; phosphoric acid; and mixtures thereof.
Abstract:
The present invention relates to a process for the manufacture of printed circuit boards. The method contemplates the use of electroless nickel as the primary medium for interconnection, for building circuitry to the desired thickness and as an etch resist. The method is particularly versatile in reducing the number of steps and variety of chemicals currently necessary to produce these circuit boards.
Abstract:
Disclosed is a method of producing vias and through holes through a metal laminate. The laminate is a multi-layer, for example, a trilayer of a relatively hard metal between two layers of a relatively soft metal. The method includes the steps of first etching a clearance hole through the soft metal on one side of the trilayer laminate, followed by partially etching the hard metal layer. Next, drilling the remaining thickness of the hard metal, and drilling through the second layer of soft metal.
Abstract:
A fusible printed circuit includes one or more conductors extending along a dielectric substrate. The circuit can be flexible or rigid. Each conductor is comprised of a layer of electrically conductive material and has one or more gaps formed in the conductive layer at locations opposite a segment of the fusible material so that electrical current flowing through each conductor is required to pass, in its entirety, through the segment of fusible material at the location of each gap in the layer of conductive material. The integral fuses are designed to specific electrical parameters and may be located randomly along circuit runs. The fusible material is cold welded to the conductors at the gaps. Pressure concentrators support the fuses and minimize motion stress on the fuses. The fuses can be sealed within a protective overlay which captures debris when the fuses are blown and controlled venting of the debris can also be provided. The use of such a circuit to incorporate a variety of fuses having different fuse ratings into the conductive paths of a printed circuit is also disclosed, as are methods of making fusible flexible circuits.
Abstract:
An electronic module assembly includes a relatively thin, bendable base plate having at least one bend axis along which the base plate is bent over on itself to provide an enclosure. An inner surface of the base plate supports at least one, and preferably two, relatively thicker metal plates, one on each side of the bend axis, each metal plate acting as a heatsink for circuit components mounted thereon.
Abstract:
A multi-layered printing wiring board and a method for manufacture where the multi-layered printing wiring board has a thermal expansion controller Copper-Invar-Copper core therein with portions of the invar core therein with portions of the Invar being selectively removed and replaced with superior materials for plating conductive material there to and further having a reduced coefficient of thermal conductivity by providing for a noble metal layer to be selectively deposited on pre-determined positions on the Copper-Invar-Copper core thereby selectively etching portions of the copper and Invar up to the noble metal layer and thereby providing for selectively removing the Invar and replacing it with a laminant material.