Abstract:
A method is disclosed of forming a high elevation area and a low elevation area in a substrate and of electrically interconnecting the high elevation area and the low elevation area. The method includes anisotropically etching into a non-masked portion of monocrystalline silicon in a selective manner of one silicon plane relative to another silicon plane to produce a high elevation area and a low elevation area which are laterally angled relative to one another. The high elevation area and the low elevation area thereby interconnected by a substantially planar, non-perpendicularly angled surface. Such areas and plane are then doped to form a continuous electrically conductive and interconnecting diffusion region extending from the high elevation area, through and along the angled surface to the low elevation area. A semiconductor apparatus having the above construction is also disclosed. Also disclosed is an epitaxial silicon growth and etching process, and a semiconductor apparatus having multiple different monocrystalline silicon portions. Further disclosed is a method of producing a testing apparatus having a projection formed essentially of electrically conductive polysilicon.
Abstract:
A method is provided for improving the integrity of a solder joint between a large surface-mounted integrated circuit component and a circuit board substrate. In particular, the strength of the solder joint is promoted by preventing the formation of voids in the solder joint during a reflow soldering process by which the component is secured to the circuit board. The method relies on the geometry of the conductor pad used to provide electrical contact between the component and the remaining circuitry and thermal contact between the component and the substrate. The conductor pad is composed of a number of platforms which are defined by a network of trenches that provides numerous passages through which the solder and flux gases may flow during the soldering process. The platforms serve as sites on which the solder compound can be selectively deposited in a manner that further enhances the soldering process, such that voids within the solder joint are substantially avoided.
Abstract:
A process for reflow mounting an electronic component includes coating a terminal electrode on a mounting board with a second solder having a second melting point higher than a reflow temperature, placing the mounting board with the electronic component on a mounting land on a conveyor which may be brought into contact with the second solder on the terminal electrode, and heating the mounting board to the reflow temperature. The terminal electrode may be coated with a solder repelling material at a selected dividing area effective for dividing the terminal electrode into a plurality of sections substantially isolated from each other in terms of solder flow. Alternatively, a mounting jig may be used for supporting the mounting board without bringing the second solder on the terminal electrode into contact with the mounting jig.
Abstract:
Disclosed is a method for manufacturing a stacked circuitized flex structure. The structure is a laminate for Z-axis communication within a parallel processor. This laminate portion provides XY plane and Z-axis interconnection for inter-processor, inter-memory, inter-processor/memory element, and processor to memory bussing interconnection, and communication. Z-axis circuitization is carried out by providing vias and through holes in individual circuitized flex strips. These vias and through holes are circuited and plated. This is followed by filling the vias and through holes with solder and forming solder bumps at the tops and bottoms of the vias and through holes. A sticker sheet with clearance holes for the solder bumps is provided, and a plurality of the circuitized flex strips are laid up for lamination to form a stack of circuitized flexible strips. Lamination is carried out at elevated pressure and temperature to crush the solder bumps, bond, and homogenize solder bump material and fuse the sticker sheets. Next, the stack is cooled to solidify the homogenized solder bump material.
Abstract:
A mounting structure for a semiconductor device which is mounted onto a metallic wiring layer formed on a surface portion of a metal printed circuit board, in which bonding portions defined by substantially square etched holes are formed in a portion of the metallic wiring layer contacting a bonding material interposed between the metallic wiring layer and the body of the semiconductor device.
Abstract:
A chip carrier mounting device which is hereinafter also referred to as an "interconnection preform placement device" includes a retaining member having a predetermined pattern of apertures in which are positioned preforms of joint-forming material such as solder. The preform retains its general configuration after the interconnection or soldering process to form a resilient joint which is more capable of withstanding stress, strain and fatique. A method of forming resilient interconnections comprises placing the interconnection retaining member device between parallel patterns of electrically conductive elements, such as the conductive pads on an electronic component and a circuit board, and effecting the bonding of the conductive elements with the preforms. The joint-forming material may be a filled solder composition or a supported solder which substantially maintain their physical shape when the solder is molten, or a conductive elastomer.
Abstract:
A microcircuit board for use with integrated circuits includes at least one thin film land to which components are to be soldered. The land is divided into solderable and nonsolderable areas, and the amount of solder that is preliminarily applied to the land will be determined by the ratio of the solderable areas to the non-solderable areas.