Abstract:
The present invention concerns the improvement of the supercurrent carrying capabilities, i.e. the increase of critical current densities, of bicrystalline or polycrystalline superconductor structures, especially of high-Tc superconductors. By providing an appropriate predetermined dopant profile across the superconductor structure, in particular within or in the vicinity of the grain boundaries, the space-charge layers at the grain boundaries are reduced and thereby the current transport properties of the superconductor significantly improved. Simultaneously, the influence of magnetic fields on the critical current densities is significantly reduced, which in turn enhances the overall supercurrent carrying capabilities while keeping the supercurrent transport properties of the grains at good values.
Abstract:
A method of evaluating configuration of solder external terminals of a BGA-type tape-based semiconductor device mounted on a board such that the external terminals are joined to lands provided on the mounting board is provided. The method includes the step of obtaining geometric data related to opening of a tape substrate of the semiconductor device, solder balls to be placed at positions corresponding to the openings, and the lands of the mounting board and the step of deribing configuration of the solder external terminal based on the geometric date. The method further includes the step of calculating the volume of voids to be produced in the external terminals, so as to compensate for the geometric data related to the tape substrate.
Abstract:
A computerized system and method for identifying and correcting bond placement errors in a bonder pre-programmed to attach connecting bonds onto bond pads of an integrated circuit by first providing a sacrificial bond pad for a sacrificial bond, then using a vision system associated with the bonder to determine the actual center of the pad as the intended bond location, and instructing the bonder to place a bond in the pre-programmed center of the pad. Second, the vision system is used to determine the actual location of the bond. Next, the error between the intended location and the actual location is determined by computing distances and directions between the pre-programmed and actual centers and the actual bond location. Finally, a new command of the bonder is computed such that a repetition of the initial error would cause the bond to be located in the actual center of another pad. This new command is input to the bonder.
Abstract:
Apparatus for promoting heat transfer between a first volume (chamber volume) and a second volume (expandable, substrate support platform volume). Specifically, the apparatus comprises: a chamber defining a chamber volume that contains a chamber atmosphere, e.g., a partial vacuum; a substrate support platform that defines an expandable volume that contains a heat transfer medium, e.g., air; and a seal that isolates the chamber volume from the heat transfer medium. The substrate support platform further comprises: a substrate support platen that has a first surface located within the chamber volume and a second surface located within the expandable volume; a housing sealed to the second surface of the substrate support platen; and a expandable member such as a bellows, attached to the housing, to provide for expansion of the expandable volume that is defined by the housing and the bellows. The housing is typically fabricated of metal and the substrate support is typically fabricated of ceramic. The seal forms a hermetic junction between the ceramic substrate support and the metal housing.
Abstract:
In a soldering method for soldering a thermit case 26 and a pair of bus bars 11a, 19a to be electrically connected to the thermit case 26, a portion to be heated P of the thermit case 26 which is spaced from the respective bus bars 11a, 19a by an approximately equal distance is heated by a gas burner 71, and solders are simultaneously supplied from solder wire supply portions 75a, 75b to a pair of solder joining faces 22 for joining the thermit case 26 and the pair of bus bars 11a, 19a, after the portion to be heated P has been heated. The temperatures of the pair of solder joining faces 22 are made substantially equal to each other by heating the portion to be heated P so that solders are simultaneously supplied to the pair of solder joining faces 22.
Abstract:
A method of making a face mask including the steps of providing a plurality of lengths of Grade 2, commercially pure titanium wire, having a diameter of from about 0.21 to about 0.24 inches; forming each length at room temperature to a desired bend angle by bending the member at room temperature using rotary bending apparatus to a first bend angle that is from about 1.25 to about 1.35 times greater than the desired bend angle; and welding each of the thus formed lengths to at least one other of the lengths in an ambient, oxygen containing environment.
Abstract:
A method and apparatus for evaluating the size and/or quality of a spot weld. The apparatus includes a two-dimensional array of ultrasonic transducers arranged with a delay line for positioning adjacent a surface of a weld. A layer of gel is placed between the delay line and the weld surface. The array of transducers emit ultrasonic waves that pass into the weld. The reflected waves are received by the transducers and relayed to a central processing unit that analyzes the time delay, amplitude, and amplitude attenuation to calculate the border of the weld nugget, the thickness of the welded material, the thickness of the gel layer, and other factors contributing to weld quality.
Abstract:
An automated method for forge welding tubulars including heating the tubular ends to be joined in a welding chamber while the heated tubular ends are maintained aligned and parallel relative to each other and at a small spacing, whereupon the heated tubular ends are pressed together while a reducing shield gas is injected into the chamber. The positions of the tubular ends are monitored by cameras which are coupled to a pyrometric and position monitoring system which automatically adjusts the position of the tubular ends relative to each other and the heat supplied to the tubular ends during the heating step until the tubular ends have reached a predetermined temperature, whereupon the tubular ends are moved towards each other along a distance which exceeds the spacing monitored between the tubular ends during the heating step with a selected extra distance, such that the tubular ends are firmly pressed against each other and the amount of external and/or internal upset of the tubular ends in the welding zone is limited to an acceptable level.
Abstract:
A rework nozzle comprises a rework duct adapted to direct a high temperature gas flow toward a rework component. The rework nozzle also comprises at least one cooling duct adapted to direct a low temperature gas flow to an area adjacent the component to maintain the adjacent area at a reduced temperature relative to a temperature of the high temperature gas flow.
Abstract:
Positive and negative electrode plates, after being dried, are layered alternately upon one another with intervening separators therebetween to constitute electrode plate groups. These electrode plate groups are transferred in succession from one to another of a plurality of preliminary chambers, which are respectively constructed to be able to create vacuum of various levels and arranged so that the vacuum level is gradually increased, and finally introduced into a processing chamber in which the vacuum level is highest, where the welding of collector plates to the electrode plate groups is performed with an electronic beam irradiating device. After that, the electrode plate groups are taken out through a post-processing chamber.