Abstract:
A method is disclosed for fabricating an electrical connection between first and second electrical pads. A solder bump is formed on the first electrical pad covering only a portion of the pad, the portion located at a side of the first electrical pad, leaving a vacant portion of the first electrical pad at the opposite side of the first electrical pad from the solder bump. The first and second electrical pads are positioned at an intersecting angle, the second pad extending towards the first electrical pad to intersect the first electrical pad at the vacant portion of the first electrical pad and at a distance less than the height of the solder bump. The solder bump is reflowed, the surface tension thereof causing the solder bump to flow into the vacant portion of the first electrical pad to contact the second electrical pad. The movement of the solder bump towards the vacant end of the first pad allows a connection to be made despite some misalignment between the first pad and the second pad. This movement therefore allows connections to be made between termination pads of an integrated lead suspension and the conductors of a multiconductor flex cable.
Abstract:
An interconnection contact structure assembly including an electronic component having a surface and a conductive contact carried by the electronic component and accessible at the surface. The contact structure includes an internal flexible elongate member having first and second ends and with the first end forming a first intimate bond to the surface of said conductive contact terminal without the use of a separate bonding material. An electrically conductive shell is provided and is formed of at least one layer of a conductive material enveloping the elongate member and forming a second intimate bond with at least a portion of the conductive contact terminal immediately adjacent the first intimate bond.
Abstract:
An apparatus and method of supporting lead fingers during a wire bonding process and of preventing the bonding apparatus and clamping assembly from applying force against the die are available. The present invention includes the use of a movable arm with a portion that is positionable under a portion of the lead fingers of a lead frame during the wire bonding process to provide increased stability of the lead fingers and prevent the bonding apparatus and clamping assembly from applying force against the die. The present invention also provides for the transfer of heat from the heat block directly to the lead fingers during the wire bonding process. The present invention includes the use of a clamp for stabilizing lead fingers during the wire bonding process.
Abstract:
In soldering together two members such as electronic circuit devices, after an oxide or contaminated layer has been removed from the surface of a solder material or bonding pad, for example, the members are aligned in an oxidizing atmosphere. Then the solder material is heated in a nonoxidizing atmosphere to melt the solder and bond the members. Cleaning of the solder material or bonding pad is performed by sputter-cleaning, laser cleaning, mechanical polishing, or cutting.
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:
An electronic component having a socketable bump grid array comprising shaped-solder coated metallic spheres is provided by a method which comprises positioning solder coated metal spheres in an aligning device having a plurality of opening corresponding to the array, the openings being tapered preferably in the form of a truncated cone with the base of the cone being at the upper surface of the aligning device and having a diameter larger than the diameter of the solder coated metal sphere. The opening is configured so that a sphere positioned in the opening extends partially above the upper surface of the aligning device. The pads of the substrate are then contacted with the positioned spheres and, when the solder is reflowed, the solder forms a bond between the conductive layer on the substrate in contact with the solder-coated metal sphere and takes the shape of the aligning device and which maintains a solder coating on the whole surface of the metal sphere. An apparatus is also provided for making such a socketable bump grid array.
Abstract:
A method for manufacturing raised contacts on the surface of an electronic component includes bonding one end of a wire to an area, such as a terminal, of the electronic component, and shaping the wire into a wire stem configuration (including straight, bent two-dimensionally, bent three-dimensionally). A coating, having one or more layers, is deposited on the wire stem to (i) impart resilient mechanical characteristics to the shaped wire stem and (ii) more securely attach ("anchor") the wire stem to the terminal. Gold is one of several materials described that may be selected for the wire stem. A variety of materials for the coating, and their mechanical properties, are described. The wire stems may be shaped as loops, for example originating and terminating on the same terminal of the electronic component, and overcoated with solder. The use of a barrier layer to prevent unwanted reactions between the wire stem and its environment (e.g., with a solder overcoat) is described. Bonding a second end of the wire to a sacrificial member, then removing the sacrificial member, is described. A plurality of wire stems may be formed on the surface of the electronic component, from different levels thereon, and may be severed so that their tips are coplanar with one another. Many wire stems can be mounted, for example in an array pattern, to one or to both sides of electronic components including semiconductor dies and wafers, plastic and ceramic semiconductor packages, and the like.
Abstract:
A method for flip-chip bonding of two electronic components (27,28) does not use a flux material. A substrate (13) of one electronic component (28) is roughened during processing to provide an improved adhesive surface for a solder ball (12). The roughened pattern is replicated by additional conductive layers formed over the substrate or in an alternate embodiment may be formed on one of the intermediary or top conductive layers. Tacking pressure is applied to the two components so the solder ball (12) will be affixed to the roughened surface and provide a temporary bond. This bond ensures the surfaces of the two electrical components remain in contact with each other during reflow of the solder ball (12) to form a permanent bond.
Abstract:
A bonding tool for use in tape automated bonding and wedge bonding of gold and gold plated leads or wires to contact pads of electronic devices is fabricated of Aluminum Oxide ceramic without electrically conductive metallic binders. The bonding tool has a microscopically rough surface that is brought into compressive contact with the gold leads or wires and manipulated ultrasonically or thermosonically in order to form a molecular bond between the gold lead or wire and the contact pad of the electronic device. The Aluminum Oxide ceramic bonding tool is sufficiently hard that it does not readily deform under normal ultrasonic bonding conditions and is not readily abraded by the gold leads.
Abstract:
A stripe terminator (18) includes a carrier plate (20) for carrying a matrix of chips (12), a carrier plate shuttle (22) for longitudinally transporting the carrier plate (20) along guide rails (24), a paste platen (26), a doctor blade for spreading a paste layer (30) on platen (26) and a paste transfer assembly (32) for transferring paste from the platen (26) to the chips (12). The carrier plate (20) is reciprocated as the paste is applied to the chips (12) to form more uniform termination stripes (14) with wraparound segments (16). A novel ribbed paste tray (72) and contoured doctor blade (74) are also disclosed for bottom side paste application.