Abstract:
Passivating layers methods for forming the same are provided for packaged integrated circuit devices. In particular, an integrated circuit die is mounted in a plastic leaded chip carrier, and a photosensitive material is then deposited over the surfaces to be passivated. Portions of the photosensitive material are then exposed to UV light, resulting in a crosslinked siloxane network. In this way, a low-temperature photodefinable passivation layer is provided for the package, with characteristics similar to conventional oxides. Advantageously, the photosensitive material can be patterned during the UV exposure, and unexposed portions selectively removed to leave the passivation layer only over desired portions of the package.
Abstract:
A method and apparatus is disclosed for sequential processing of integrated circuits, particularly for conductively passivating a contact pad with a material which resists formation of resistive oxides. In particular, a tank is divided into three compartments, each holding a different solution: a lower compartment and two upper compartments divided by a barrier, which extends across and partway down the tank. The solutions have different densities and therefore separate into different layers. In the illustrated embodiment, integrated circuits with patterned contact pads are passed through one of the upper compartments, in which oxide is removed from the contact pads. Continuing downward into the lower compartment and laterally beneath the barrier, a protective layer is selectively formed on the insulating layer surrounding the contact pads. As the integrated circuits are moved upwardly into the second upper compartment, a conducting monomer selectively forms on the contact pads prior to any exposure to air. The integrated circuits can then be transferred to an ozone chamber where polymerization results in a conductive passivation layer on the contact pad.
Abstract:
A conductive plastic lead frame and method of manufacturing same suitable for use in IC packaging. In a preferred embodiment, the lead frame is constructed of a plastic or polymer based lead frame structure with an intrinsic conductive polymer coating. In a second embodiment the lead frame is a composite plastic or polymeric material intermixed with an intrinsic conductive polymer coating.
Abstract:
A semiconductor package with thermally enhanced properties is described. The semiconductor package includes a substrate upon which a die is affixed. The die and the substrate each have contacts which are respectively connected with each other. A heat sink is affixed to a surface of the die by way of a thermally compliant material. The compliant material reduces the stresses caused by temperature fluctuations which cause the heat sink and the die to expand and contract at different rates. A first molding material is deposited around the periphery of the die, compliant material and heat sink, thereby leaving exposed substantially an entire surface of the heat sink.
Abstract:
A socket device for receiving a connection pin is disclosed, the socket device including a substrate having an upper surface. The socket device includes a connection pad disposed on the upper surface and a first layer disposed on the upper surface and on the connection pad. The first layer includes material having an overall positive coefficient of thermal expansion. The socket device includes a second layer disposed on the first layer. The second layer includes material having an overall negative coefficient of thermal expansion. The socket device also includes a contact hole formed in the first and second layers exposing a portion of the connection pad.
Abstract:
The present invention is drawn to a method of lowering the net resistivity of an interconnect by depositing a monomer layer upon an aluminum bonding pad, the treatment thereof to cross link the monomer to form an electrically conductive polymer, and simultaneously, the substantial reduction of alumina, Al.sub.2 O.sub.3, to metallic aluminum. In the method of the present invention, deposition of a monomer layer in a solvent, volatilization of the solvent, and contact with a strong oxidizer such as a potassium permanganate allows for the use of the strong oxidizer without the hindrance of having to deal with a manganese oxide husk on the surface of the aluminum bonding pad. Preferably, the chemical qualities of the monomer will include the tendency to be a reducing agent to the native oxide film of the bonding pad. By selecting a monomer that tends to reduce rather than to oxidize, the problem of thickening the native oxide film is avoided. Another preferred chemical quality of the monomer and its polymer after cross linking, is that it will act as a protective coating to the chip package for substantially all further processing. In particular, the monomer or its cross-linked polymer will act as a protective coating to the chip package during an acid dip in an oxidizer solution such as acidic KMnO.sub.4.
Abstract:
A quad in-line memory module (QIMM) includes a circuit board having top and bottom edge connectors and a number of memory devices mounted on each side of the circuit board. Generally, half of the memory devices are electrically connected to the bottom edge's connector and half are electrically connected to the bottom edge's connector. One edge of the QIMM can be connect directly to a computer system's memory bus. The other edge can be connected to operated as a cache memory or a video memory.
Abstract:
Conductive interconnections are formed by depositing an adhesive material, made up of ferromagnetic particles dispersed within a matrix material, on a semiconductor substrate, such as an electronic component, and applying a magnetic field between an exposed surface of the adhesive material and an attached surface of the adhesive material (abutting the semiconductor substrate), such that a plurality of the ferromagnetic particles move and align within the matrix material under the influence of the magnetic field. One method of the present invention comprises depositing the adhesive material on a contact site of a first electronic component. A second electronic component having a contact site is aligned over the adhesive material and a magnetic field is applied between the first electronic component and the second electronic component. The first electronic component and the second electronic component are then pressed together such that a portion of the plurality of the ferromagnetic particles makes electrical contact with both the first electronic component bond pad and its corresponding second electronic component bond pad.
Abstract:
A disposable screen used in a screen printing system for printing onto electronic devices is formed of a non-metallic material. The screen is patterned from a foil. The material can be selected from a group consisting of plastic, nylon, paper, and resin. A disposable screen is mounted in the screen printing system, after which a paste material (including solder or an adhesive such as polyimide, bismaleimide, or a thermoset or thermoplastic compound) can be printed through the screen to a target structure. The used screen is discarded after one or more uses and a new screen is mounted in the screen printing system. A teaching sheet having a disposable transparent film is also used to set up the screen printing system. The film is detachably attached to a frame. After one or more prints, the used film is detached and replaced with a new film.
Abstract:
A stacked semiconductor die assembly includes at least two partially offset semiconductor dice with bond pads located adjacent at least one peripheral side thereof supported on a redistribution element formed of a material of substantially similar CTE to that of the dice, and a paddle-less lead frame secured to the redistribution element during fabrication, including encapsulation. The assembly is configured to be substantially vertically symmetrical with respect to inner ends of lead fingers of the lead frame to facilitate uniform encapsulant flow. The semiconductor die assembly may be configured in a package with leads extending from two sides thereof, such as a thin small outline package (TSOP), or four sides thereof, such as a quad flat pack (QFP).