Abstract:
Interconnection elements for electronic components, exhibiting desirable mechanical characteristics (such as resiliency, for making pressure contacts) are formed by shaping an elongate element (core) of a soft material (such as gold) to have a springable shape (including cantilever beam, S-shape, U-shape), and overcoating the shaped elongate element with a hard material (such as nickel and its alloys), to impart a desired spring (resilient) characteristic to the resulting composite interconnection element. A final overcoat of a material having superior electrical qualities (e.g., electrical conductivity and/or solderability) may be applied to the composite interconnection element. The elongate element may be formed from a wire, or from a sheet (e.g., metal foil). The resulting interconnection elements may be mounted to a variety of electronic components, including directly to semiconductor dies and wafers (in which case the overcoat material anchors the composite interconnection element to a terminal (or the like) on the electronic component), may be mounted to support substrates for use as interposers and may be mounted to substrates for use as probe cards or probe card inserts. In one embodiment, a hybrid composite interconnection element is formed by mounting a core to an end of an flat elongate element formed from a sheet, and overcoating at least the core, the flat elongate element providing a "floating" support for the overcoated core, capable of absorbing non-planarities (tolerances) of an electronic component. Methods of fabricating interconnection elements on sacrificial substrates are described. Methods of fabricating tip structures and contact tips at the end of interconnection elements are described.
Abstract:
A surface mounting stress relief system for mounting a surface mount package such as a leadless ceramic chip carrier on a printed circuit board includes a printed circuit board having a top layer attached to a bottom layer. The top layer includes cavities for exposing top surface portion of the bottom layer which carry a plurality of solder pads. The surface mount package is positioned on the printed circuit board for placing the package bottom surface on a top surface of the printed circuit board between the cavities while positioning package contact pads in spaced relation above corresponding preselected solder pads. A solder column extends between each of the plurality of corresponding solder pads and the selected contact pads for providing an electrical connection. The solder column is formed by applying a solder paste to the solder pads on the printed circuit board, screening a low temperature solder paste onto each of the contact pads of the surface mount package, placing a solder ball onto each pad, and attaching the solder ball to each of the contact pads of the package by passing the package through a reflow oven for reflowing the low temperature solder paste without reflowing the high temperature solder ball.
Abstract:
Resilient contact structures are mounted directly to bond pads on semiconductor dies, prior to the dies being singulated (separated) from a semiconductor wafer. This enables the semiconductor dies to be exercised (e.g., tested and/or burned-in) by connecting to the semiconductor dies with a circuit board or the like having a plurality of terminals disposed on a surface thereof. Subsequently, the semiconductor dies may be singulated from the semiconductor wafer, whereupon the same resilient contact structures can be used to effect interconnections between the semiconductor dies and other electronic components (such as wiring substrates, semiconductor packages, etc.). Using the all-metallic composite interconnection elements of the present invention as the resilient contact structures, burn-in can be performed at temperatures of at least 150.degree. C., and can be completed in less than 60 minutes.
Abstract:
A clip lead is provided for soldering to and supporting a first substrate vertically on a second substrate which may be horizontal. The terminal end of the clip is configured to form a stable support for the substrate during soldering in a vertical position to the second substrate by being bent at right angles to and extending under the first substrate.
Abstract:
A method for electrically bonding surface-mountable integrated circuits (LLCCC-components) onto a printed circuit board. A specially shaped flexible bonding element having a semicircular central portion is used to flexibly connect the LLCCC components to the circuit board so that stresses due to thermal expansion of the components are absorbed.
Abstract:
Pin-shaped or flat-plate-shaped parallel terminals of an electronic or piezoelectric component for being inserted in through holes formed in a printed circuit board. The terminals are electrically connected to electrodes of the electronic component and arranged substantially parallel to each other. Each of the terminals includes a bent portion formed at a location along an axis of each terminal so as to project at least partially in a direction perpendicular to that, and the bent portions are generally at an imaginary surface defined by the terminals.
Abstract:
Subject-matter of this invention is a method for assembling components, such as M.O.S, devices and the like, upon printed circuit boards by clinching, such method including the steps of providing a board bearing a printed circuit with places upon which a component is to be assembled; applying the component upon the board with its pins in contact with the places of the circuit among which it is to be assembled; pressing the component in order that the pins are forced to penetrate through the thickness of the board; and clinching the end portions of the pins protruding from the back side of the board.
Abstract:
The present invention is drawn to an electronic component in the form of a packaged semiconductor device or the like, and an electronic apparatus using the same, in which protrusions having a semicircular cross section are formed along the sides of the lower surface of the package, leads of the component include a first curved portion conformed to the contour of a protrusion, a second curved portion conformed to the lower surface of the first curved portion and a linking portion coupling the first and second curved portions. The leads project from the side of the package, and the lower surface of the second curved portion is soldered to the wiring pattern on a printed circuit board. With this structure, if the electronic component becomes defective, the package can be lifted from the surface of the printed circuit board by stretching the external leads, and the solder can be removed very easily. Accordingly, even if multiple electronic components are densely mounted on the printed circuit board, an individual defective electronic component can be easily replaced.
Abstract:
An electrical connector comprising a header with a plurality of terminal pins having means for retaining the header in position during soldering to a printed circuit board. Retention is accomplished by an offset formed as a crimp at the insertion end of at least one pair of terminals. The crimps exert opposite normal forces against one surface of their respective holes to retain the header during soldering.
Abstract:
A compliant S-shaped lead for resiliently supporting an integrated circuit chip package in spaced relation generally parallel to a printed circuit board. The S-lead bends and twists to absorb forces which would otherwise be exerted on solder joints due to temperature cycling and vibration. The symmetrical S-lead self-centers on both the package and PC board to provide minimum stress. The leads are held by a support strip for connection to the chip carrier. Thereafter, the support strip is removed and the carrier positions the leads for connection to the circuit board.